CULTURE SYSTEM COURSE NOTES

Course Map

1) Definition and importance

- definitions and importance

- objective of the systems approach and definition of the elements of the system

2) Type of cultivation system

3) Evaluation of cropping systems

4) Relationship between components in cropping systems

Course objective:

1- Definition

A system : is a set of components interacting functionally within well-defined limits. Able to respond as a

whole to external stimuli: it is not directly affected by its own results.

Ecosystem : Any set of organisms that interact or have the potential to interact with the physical

environment in which they live, to form an ecological system or ecosystem. Ecosystems are not static

entities; they are dynamic systems with a characteristic pattern of energy flow, nutrient cycling, and

structural change.

Agro-ecosystem: is a set of plants and animals interacting with their modified physico-chemical

environment, to produce food, fibers, energy or any other product entering directly into human food or for

transformation. Agro-ecosystems are structurally and dynamically complex artificial. But their complexity

results from the interaction between socio-economic and ecological processes.

Culture system: Is a set of plants of the same species or of different interacting species, in a more or less

defined spatio-temporal arrangement, completing their vegetative and / or cultural cycle by exploiting the

resources of the environment on a well-defined area.

The cultivation system includes the edaphic component (soil), the biological component (plants and

animals (insects and microorganisms)). Culture is a subsystem of

cultivation system. For example, in a corn-cotton cropping system, corn as a crop is a subsystem of the

overall system.

Culture systems: Cropping systems, an important component of an agricultural production system,

represent a pattern of cultivation used on a farm and their interaction with the farm's resources, other farm

businesses and available technologies, which determine their composition. It is defined as the order in

which crops are grown on a piece of land for a specified period of time or the cropping system is the way in

which different crops are grown. In cropping systems, several crops may be grown together or grown

separately at short intervals in the same field.

Culture model:

This is the cultivation pattern for a given piece of land. The crop diagram indicates the proportion of the

area devoted to various crops at a given time in a unit of area or the annual sequence as well as the spatial

arrangement of the crops which follow one another in an area.

The crop model and its management is used to derive benefits from a given resource base under specific

environmental conditions. The culture model provides important information on the type of environmental

resource management as well as the main negative or positive effects that may occur. As land resources

are limited, emphasis should be placed on increasing production per unit area over the course of a year.

Cropping systems are based on the predominant type of environmental condition (climate, soil and water

availability). They must be developed to reach potential production levels through efficient use of available

resources. The cultivation system should provide enough food for the family, fodder for livestock, and

generate enough cash income for household expenses and cultivation expenses.

Efficient cultivation systems:

Efficient cropping systems for a particular farm operation depend on the farm's resources, farm businesses,

and farming technologies. The farm is an organized economic unit. Factors of production
include land, labor, capital and infrastructure. When land is limited, intensive cultivation is adapted to make

full use of the available water and labor. When labor is sufficient and cheap, vegetable crops are also

included in cropping systems because they require more labor.

Importance of the systems approach

In the systemic approach, all components and activities are linked, they influence each other. It is not

reasonable to consider a component alone without recognizing that what it does and what happens to it will

affect other parts of the system. Management practices in cropping systems globally influence the system

and all subsystems are affected.

The systematic approach draws its importance from the efficient management capacity that it offers, by

considering each element on the one hand, but not without determining their impact on the other elements

according to a spatio-temporal scale defined by the farmer. The soil is the main support for plant production in

Cameroon, it would be unwise to consider that the previous crop of a soil does not influence the following crops.

Failure to take into account the consequences of the previous crop on the components of the system that will be

reused can lead to under-production, leading to a decrease in income.

Objective of the systems and components of cropping systems approach

The goal of any cropping system is the efficient use of all resources, namely land, water and solar radiation,

maintaining the stability of production and achieving higher net yields. Efficiency is measured by the

quantity of product obtained per unit of resource used in a given time and over a defined space. Crop

systems are made up of four (04) elements:

- The genotype (s)

- Floor

- The farmer

- The environment above the ground

These elements must be taken into account for the establishment of sustainable cropping systems.

The genotype (s)

Represent all the plants of the same species, of different species, of an equivalent or different cycle that will

be used simultaneously, or in a staggered manner over a defined space.

The choice of genotypes must not be random, this choice must be based on the collaboration between the different

genotypes on the one hand, the genotypes and the soil on the other hand, the production objectives set by the farmer,

the particular environmental characteristics. which they require.

Floor

Land taken as a factor of production refers to its availability in terms of available surface. As subsystems

refers to its physico-chemical and biological quality. The needs of each genotype for the physical

characteristics of the soil should be known, as well as the nutrient requirements and the water holding

capacity of the soil. These characteristics specific to each genotype must be known and controlled in order to

determine the probable effects of the action of each genotype on the soil.

As an example, the establishment of a corn crop in relay with the potato whose respective needs in terms of

NPK are 200-100-100 and 150-100-150 for the formulation of a yield of 6 and 25 t / ha respectively. Will lead

to a not insignificant and rapid depletion of the soil for all NPK elements, although the effects from year to

year will be different, more pronounced for the element with the most deficit, the soil reservoir not containing

the equal amounts of each element.

The farmer

By recalling the notion of agroecosystem, man is the stone at the center of the building that is agriculture. The right

combination of the components of the system therefore depends on its knowledge of its needs on the one hand

and its resources on the other. However, there is a component on which the farmer cannot act, the environment.

The environment

The environment is taken here in the sense of the prevailing climatic conditions. It is very difficult to act on

the climate, but it is not impossible, however we do not have in Cameroon the technology to do it. In

addition, the climate mosaic we have is an advantage. Knowledge of minimum and maximum

temperatures, the cumulative height of monthly precipitation, its distribution, the start and the end of the

rains is
more than necessary for the establishment of an efficient system. Allowing the efficient use of other

components and deriving maximum satisfaction from the production activity.

Different cropping systems

Classifications of cropping systems:

Depending on the resources and available technology, different types of cropping systems are adopted in

the farms, which are as follows

Monoculture: Monoculture involves growing only one crop on a given land, year after year. Or the practice

of growing only one crop on a piece of land year after year, such as growing only corn, or soybeans or

green beans each year on the same land. This is due to climatological and socio-economic conditions or to

the specialization of a farmer in a particular crop.

Multiple crops or polyculture: It is a cropping system in which two or three crops are sown each year on

the same plot of land. Growing two or more plants on the same piece of land in a calendar year is called a

multiple crop. It is the intensification of crops in time and space, that is, more crops in a year and more

crops in a year. the same parcel of land at a given time. It includes intercropping, mixed cropping and

sequential cropping.

The crop intensity is greater than 200% if we consider the entire farm; the multiple crop index (MCI) is

determined by the number of crops and the total area planted divided by the total area of arable land.

When the value is equal to or greater than three, it is said to be the most promising farm. This is also called

intensive cultivation.

1. Polyculture: the cultivation of more than two types of plants grown together on a piece of land during a

growing season. for example

Corn + Papaya + plantain + Macabo.

Relay culture: consists of placing the next crop when the previous crop is at its stage of maturity, or

sowing the next crop immediately after

harvest of standing crops. It is also a cropping system in which one crop sits above the earth and quickly

succeeds the next crop, for example

Overlapping cultures: In this system, the next crop is sown in the growing crop before harvest. Thus, in

this system, a crop is sown before the harvest of the previous crops.

Intercrop culture: Growing two or more plants simultaneously on the same plot of land with a defined row

scheme, for example growing soybean + maize in a 5: 1 ratio, i.e. one row of maize sown every 5 soybean

lines. We thus obtain an intensity of culture in the spatial dimension.

Multiple crops in the form of intercropping are predominant in the dry, humid and semi-arid tropics.

Multiple sequential cultures

Sequence cropping: Sequential cropping is defined as the cultivation of two or more plants in sequence on

the same plot of land during a farming year. The intensification of crops only has a temporary dimension

and there is no competition between crops.

Depending on the number of crops grown in a year, we speak of double, triple and quadruple cultivation

involving respectively two, three and four crops, for example double cultivation: 1. Rice - potato / mustard 2.

Sorghum - gram; Triple culture: 1. Rice

- potato - peanut 2. cowpea - mustard - jute; quadruple cultivation: Groundnut of the Kharif

- leafy vegetables - wheat - summer green - gram.

Systems with more than three crops: Bradfield experimented at IRRI, Philippines, with different crop models

that could maximize productivity per unit area. The most successful model has been a sequence of five

crops including rice, sweet potato, soybean, sweet corn and green soybean. The tillage pattern varied for

each crop and the number of days to harvest was 102, 100, 85, 66 and 60 respectively. This pattern gave a

gross income three times higher than that normally obtained in a rice pattern. .

Ratooning: Refers to growing a plant whose regrowth comes out of the roots or stems after the crop is

harvested, although this is not necessary for cereals.

Crop rotation: Refers to the recurrent succession of crops on the same piece of land, either over the

course of a year or over a longer period. The component crops are chosen so as not to harm the health of

the soil. Or it is a matter of cultivating a set of crops in regular succession on a piece of land for a specific

period of time, with the aim of obtaining maximum profit with minimum investment without impairing soil

fertility. Example, sorghovouandzou, groundnut - maize.

Crop rotation and its characteristics

Characteristics of a good crop rotation:

- It must be able to adapt to existing pedological, climatic and economic factors.

- Sequential cultivation adopted for a specific area should be based on adequate land use or be organized
in relation to fields so as to maintain crop yields and allow accumulation of soil organic matter.

- The rotation should include a sufficient area under the soil improvement crops (legumes) to maintain and
also increase the organic matter content of the soil.

- In areas where legumes can be grown successfully, rotation should provide sufficient area under legumes
to maintain the soil "N" supply.

- It should provide food grains, legumes, oilseeds, etc. to families and roughage, from fodder to cattle.

- It should provide a maximum area under the most profitable crops and adapted to the region.

- It must be organized in such a way as to allow an economy of production. The increase in crop yield is
mainly due to the maintenance of the physical and chemical properties of the soil. Soil fertility is restored
by fixing atmospheric nitrogen, encouraging microbial activity (more organic matter) and protecting the soil
from erosion, salinity and acidity.

- It contributes to the fight against insects, parasites and soil diseases. It also helps to fight against weeds.
- Prevent or limit periods of peak irrigation water needs. Crops requiring heavy irrigation if followed by light
irrigation, it will not affect or deteriorate the physical condition of the soil.

- It facilitates a fair distribution of work. The following culture helps to use all resources and inputs correctly.
Family and farm labor, energy, equipment and machinery are well utilized throughout the year.

- Inclusion of crops from different feeding zones (root system) and different nutrient requirements could
maintain the best balance of nutrients in the soil.

- Crop diversification reduces the risk of financial losses due to unfavorable conditions.

- It improves soil structure, percolation and reduces changes in creating the hard layer in the subsoil and
also reduces soil erosion.

- Family needs for animal feed, food, fuel, fiber, spices, sugar, etc. are met and also meet the needs of
livestock.

- Benefits of producing short-lived crops (catch crops / crops) when long-season crops cannot be grown for
some reason.

Factors to consider when planning a crop rotation: Growing different plants is very beneficial, but

sometimes the desired crops cannot be grown due to certain determining factors (soil and climate),

irrigation, availability of oxen and other powers, market facilities and type of agriculture.

The objectives of intercropping systems are:

- Insurance against loss of the main crop in the event of bad weather conditions or pest epidemics.

- Increase and maintenance of total productivity per unit area.

- Judicious use of resources such as land, labor and inputs.

Originally, intercropping was practiced as an insurance against crop failure under rainfall conditions.

Currently, the main objective of intercropping is to increase productivity by unit area more stability
from production. Intercropping systems use sufficient resources and their productivity is increased.

Based on the percentage of the plate population used for each crop in the intercropping system, it is

divided into two: additive series and replacement series.

Additive series: Mainly adopted in India, a crop is sown with 100% of its recommended population in pure

stand, which is known as the staple crops. Another crop, called an intercrop, is introduced into the base

crop by adjusting or changing the geometry. The additive series is more effective than the replacement

series in the intercropping system.

Replacement series: the two cultures are called component cultures. By scarifying a certain proportion of

the base population, another component is introduced. This type of intercropping is practiced in Western

countries.

Component culture: Is used to denote the individual crops that make up the intercropping situation. The

intercrop yield is the yield of each component crop, expressed over the total area of the intercrop.

Basic culture: this is the one that is planted as the optimum population in an intercropping situation, and

the second crop is planted between the rows of the staple crop to get additional yield from the intercrop

without affecting the yield of the intercrop crop. based.

- The intercropping system uses resources efficiently and their productivity is increased (Reddy and Reddi,
1992).

Types of intercropping:

at. Mixed intercrops: Simultaneous cultivation of two or more plants without separate row arrangement.

b. Row intercrops: Simultaneous cultivation of two or more plants, one or more of which are planted in a

row.

vs. Intercropping in strips: Simultaneous cultivation of two or more plants in different bands, wide enough

to allow independent cultivation but narrow enough for the plants to interact ergonomically.
d. Intercrops in LERais: Grow two or more plants simultaneously for part of the life cycle of each. A

second crop is planted after the first has reached its reproductive stage but before it is ready for harvest.

Translated with www.DeepL.com/Translator (free version)

Intercropping can be divided into four groups (Singh 1990).

i) Parallel crops: As part of this culture, two crops are selected, which have different growth habits and

which do not compete with each other, and both of which express their full yield potential. For example: 1)

Green gram or black gram with corn 2) Green gram or soybean with cotton.

ii) Support crops: In companion cultivation, the yield of one crop is not affected by the other, in other

words, the yield of both crops is equal to that of their pure crops. That the standard plant population of the

two crops be maintained, for example: 1) Mustard, wheat, potato, etc. with sugar cane 2) Wheat, radish,

cabbage, sugar beet, etc. with potato.

iii) Multi-storey culture: Growing plants of different heights in the same field at the same time is called

multistage cultivation. It is mainly practiced in orchards and plantations for maximum use of solar energy

even in case of high density of plantation. For example 1) Eucalyptus + Papaya + Berseem, 2) Sometimes

it is practiced under field crops such as sugar cane + potato + onion

3) Sugar cane + mustard + potato 4) Coconut + pineapple + turmeric / ginger.

iv) Culture on a stratum: Intercropping is most prevalent in plantation crops like coconut and areca nut.

The different crops, varying in height, rooting and duration, are called tire crops.

The goal of this growing system is to use vertical space more efficiently. In this system, the taller

components have foliage tolerant of strong light and high evaporation demand and the shorter component

(s) have / have foliage requiring shade and / or relatively high humidity. for example: coconut + black

pepper + cocoa + pineapple.

Mechanism of yield advantage in intercropping

The most important index of biological advantage is the total LER ative yield (RYT) introduced by De wit or Land

van Den Bergh (1965) or the land equivalent ratio by Willey (1979).

1. The yield of a component crop in an intercrop system, expressed as its pure crop yield, is the ative LER

yield of the crop, and the sum of the ative LER yields of the crops comprising the system is called the total

ative LER yield ( RYT).

2. The total area of land required for monoculture to achieve the same yields as intercropping is called the

Land Equivalence Ratio (TER). The two expressions (RYT and LER) are similar.

Management of intercropping systems

In the intercropping system, crops are grown simultaneously. Management practices aim to provide a

favorable environment for all components, to exploit a favorable interaction between component cultures

and to minimize competition between components.

at. Preparation of the seedbed: The goal of soil preparation is to establish an ideal area for sowing that

minimizes stress. Conditions of potential stress include insufficient or excessive humidity, unfavorable

temperature for a given species, soil crusting, weeds, residue from the previous crop, and attack by insects

or pathogens. The importance of the seedbed is the same in conventional cultivation (monoculture) and in

multiple crops. The preparation of the seedbed depends on the crop. Deep-rooted crops respond to deep

plowing while for most cereals shallow tillage is sufficient. Small seed crops require a fine seedbed, cotton

and corn, planted on ridges, some crops on a flat seedbed. As several crops are planted as intercrops, the

seedbed is usually prepared according to the needs of the basic crop.

b. Varieties: The component crop varieties in the intercropping system should be less competitive with the

staple crop and the peak nutrient demand period should be different from that of the staple crop. The

minimum difference between the maturity periods of two components should be 30 days. Varieties selected

for intercropping should have thin leaves, tolerate shade and be

less branched. If the basic crop is shorter than the intercrop, the intercrop should be compact with an erect

branching and its early growth should be slow. The characteristics of the base culture must be the same as

those of the single culture.

vs. Sowing: Sowing practices are slightly modified to accommodate intercropping, so that they cause less

competition to the staple crop. Widening the row spacing of the grain components to accommodate a

greater number of rows of the legume crop components improves the yield of the staple crops and the

efficiency of the intercropping system. The sowing of the basic crop is done either in paired rows, or in

wider paired rows, or in row hopping of the basic crop, reducing the spacing between the rows. The

spacing between two pairs of rows is increased to take account of inter-culture. Such an arrangement of

staple crops at Row interior improves the amount of light transmitted to the crop of the lower component,

which can improve the yield of legumes in the grain + legume intercropping system. Plantings can be

staggered in order to increase the time difference, which could result in a higher yield advantage.

d. Fertilizer application: Nutrient uptake is generally greater in intercropping systems than in pure crops. When the legume is

combined with a cereal crop in an intercropping system, the legume supplements part of the nitrogen required for the cereal crop;

the amount can be 20 kg / ha for legumes. Applying a higher rate of nitrogen in the grain + legume intercropping system not only

reduces the nitrogen fixing capacity of legumes, but the legume's growth is also suppressed by the rapid and aggressive growth.

cereals. Intercropping cereals + legumes is therefore mainly advantageous in case of low fertilizer application. Considering all the

factors, it is suggested that the nitrogen dose recommended for the basic crop as a pure crop is sufficient for the intercropping

system with cereals + legumes or legumes + legumes. For phosphorus and potassium, one-eighth to one-quarter of the

recommended rate for intercropping is also added to the recommended rate for staple crops to meet the additional demand. The

base rate of nitrogen is applied to the rows of both components in intercrops one-eighth to one-quarter of the recommended rate for

intercropping is also added to the recommended rate for staple crops to meet the additional demand. The base rate of nitrogen is

applied to the rows of both components in intercrops one-eighth to one-quarter of the recommended rate for intercropping is also

added to the recommended rate for staple crops to meet the additional demand. The base rate of nitrogen is applied to the rows of

both components in intercrops

cereals + legumes. Nitrogen is only applied to the grain rows. P and K is applied as the base rate to both

crops.

e. Water requirements: The water management technique is the same for solitary cultivation and

intercropping or sequential cultivation. However, the presence of an additional culture can have a

significant effect on evapotranspiration. With good water management, it is possible to grow two crops

while normally only one is grown under a rain feed. The intercropping system is generally recommended in

rain-fed situations to achieve stable yields. The total water requirements of intercropping do not increase

much compared to those of monoculture. At ICRISAT, the water requirements of sole and intercrop with

red gram were almost similar (584 and 585 mm, respectively).

However, in a more competitive crop like onion, intercropping peanuts increases the total water

requirement by about 50mm. The total amount of water used in the intercropping system is almost the

same as in single crops, but the yields are higher. The efficiency of water use in intercrops is therefore

higher than that of single crops. Water scheduling: If one crop is irrigated according to its needs, the other

crop may suffer from excessive water stress, sometimes resulting in total crop failure.

f. Weed management: It is generally believed that intensive cultivation reduces weed problems. Weed

infestation depends on the crop, the density of the plant and the cultivation operation performed. Weed

problems are less in intercrop systems than in single crops. This is due to the complete coverage of the

surface due to the high density of plants in intercrops which cause severe competition with weeds and

reduce their growth. The weed control capacity of the intercrop depends on the constituent crops selected,

the genotype used, the density of the plant adopted, the proportion of constituent crops, their spatial

arrangement and the condition of the crop. soil moisture in terms of fertility. The experiment carried out at

ICRISAT, Hyderabad, indicated that intercropping reduced weed infestation by 50-75%.

Chemical weed control is difficult in intercrops because the herbicide may be selective for one crop but not

selective for another. Nicosulfuron

(Selective Corn Herbicide) provides weed control in corn sole, but is not suitable for the corn + mucuna

intercropping system, as it is toxic to mucuna.

g. Pests and diseases in the intercropping system: Pests and diseases are believed to be less in

intercropping systems due to crop diversity than in single crops. The spread of disease is affected by the

presence of different crops. The small leaf of Brinjal is less important when the Brinjal is sheltered by maize

or sorghum, because the insect carrying the virus first attacks maize or sorghum; the viral infestation is less

important on the Brinjal. Non-host plants in mixtures can emit chemicals or an odor that affects the pests,

thus protecting the host plants. The concept of crop diversification for the management of nematode

populations has been applied mainly in the form of decoy and trap crops. Decoy cultures are non-host

cultures, which are planted so that nematodes waste their potential for infection. This potential is affected

by the activation of nematode larvae in the absence of hosts by the bait cultures.

Management of the sequential culture system

Unlike intercrops, the crops are grown one after the other in sequential cultivation and, therefore, the

management

The practices are different.

at. Preparation of the seedbed: A suitable seedbed can be prepared depending on the crops. Ponds for

rice, ridges and furrows for vegetables, corn and cotton and a flat seedbed for several other crops.

However, two problems arise when preparing the seedbed in a sequential culture system.

1) The time available for seedbed preparation is less in high intensity cropping systems. Frequent rains

disrupt land preparation.

2) Due to the impediment, the crop field may be in good condition. For example, preparing the field after

rice is difficult, it is mainly because the soil structure is destroyed during the formation of puddles. The

rotation time, the time between harvesting and sowing the next crop is more important if the rice is the

previous crop. To avoid this problem, we adopt minimum tillage or zero tillage. It is common to sow

legumes just before or immediately after harvesting the rice. In agriculture

irrigated, the time available for tillage between two successive crops is minimal, which leads to minimum

tillage. Minimum tillage is applicable for soils with,

1. A favorable soil texture

2. Good drainage

3. Strong biological activity of soil fauna.

4. Adequate amount of soil residue mulch and

5. Favorable initial soil moisture and friable soil consistency over a wide range of soil moisture.

Zero or minimal tillage is not possible in all sequential cropping systems. If sunflower is the previous crop,

plowing is essential to oxidize sunflower allochemicals. Pearl millet and sorghum stubbles, which contain a

high C / N ratio, immobilize nitrogen. It is therefore necessary to eliminate them. Stubble also disrupts field

operations.

b. Varieties: Short-lived crops are selected to fit well into multiple crop systems. Photosensitive varieties

are essential for the success of the sequencing system. Most high yielding varieties.

vs. Sowing: Sowing is not a problem because there is sufficient time for the preparation of the seedbed. If

the seedbed is not well prepared, the establishment of the culture is difficult. For example, the

establishment of cotton is difficult in black soil after rice. Due to the hardness of the surface layer,

penetration of the roots is difficult.

d. Management of soil fertility: The management of soil fertility becomes more complex in intensive crops

due to the residual effect of nutrients applied to previous crops, the possible effect of legumes in the

system, the complementary and competitive interaction of the constituent crops and the influence of crop

residues left in the soil. Modern or chemical agriculture, which includes more intensive crops involving

improved varieties, higher inputs of fertilizers and water, increased yields and accelerated removal of plant

nutrients, has added new dimensions to the crop. fertility management. Fertilization practices for cultivation
Sequential: Based on long-term fertility experiments conducted in various regions of India, the following

main conclusions are drawn:

- The productivity of the system increased with the application of P at the same time as N, and further increased
with the use of N, P and K. The application of N at the recommended dose is recommended for each crop of the
cropping system.

- The management of phosphorus in the cropping system requires a careful adjustment of the dose of fertilizer P
taking into account the type of fertilizer, the characteristics of the soil and their level of yield, the importance of
removing the P and the growth environment.

- The removal of K in proportion to nitrogen is very high in cropping systems, especially those involving
cereal and fodder crops. It is important to apply K fertilizer at the recommended rate to maintain soil
fertility. In soils rich in K, application of 50% of the recommended rate of K for each crop in the may be
optimal.

Crop System and Integrated Nutrient Management (INM): The concept of Integrated Nutrient Management (INM) involves the use of

various sources of inorganic, organic and biological nutrients to improve and maintain soil fertility, enabling sustainable crop production. Crop

responses to organic and biological sources of nutrients for improving and maintaining soil fertility lead to sustained agricultural production:

Crop responses to organic and biological sources of nutrients are not spectacular in terms of concerns fertilizers, but we know that the

complementary use of these resources improves the efficiency of the use of applied fertilizers, in addition to improving the physico-chemical

properties of the soil and preventing the appearance of micro-deficiencies in nutrients. The main components of MNI are fertilizers, organic

fertilizers, green manures, crop residues and biofertilizers. In cereal-based cropping systems, about 25-50% of the NPK fertilizer dose of rainy

season crops could be reduced by the use of organics such as FYM, green manure and residues. of culture. In sugarcane cultivation systems,

the integrated use of sulphite press slurry, cane waste and biofertilizers, each with inorganic fertilizers and green manure, has shown a saving

of 20 to 25% of N fertilizers applied to sugar cane improving the efficiency of use of N, P and other nutrients. organic fertilizers, green manures,

crop residues and biofertilizers. In cereal-based cropping systems, about 25-50% of the NPK fertilizer dose of rainy season crops could be

reduced by the use of organics such as FYM, green manure and residues. of culture. In sugarcane cultivation systems, the integrated use of

sulphite press slurry, cane waste and biofertilizers, each with inorganic fertilizers and green manure, has shown a saving of 20 to 25% of N

fertilizers applied to sugar cane improving the efficiency of use of N, P and other nutrients. organic fertilizers, green manures, crop residues

and biofertilizers. In cereal-based cropping systems, about 25-50% of the NPK fertilizer dose of rainy season crops could be reduced by the

use of organics such as FYM, green manure and residues. of culture. In sugarcane cultivation systems, the integrated use of sulphite press

slurry, cane waste and biofertilizers, each with inorganic fertilizers and green manure, has shown a saving of 20 to 25% of N fertilizers applied

to sugar cane improving the efficiency of use of N, P and other nutrients. In cereal-based cropping systems, about 25-50% of the NPK fertilizer dose of rainy season c

The factors for determining the fertilization schedule are as follows

o The soil that provides energy

o Total uptake by crops

o Residual effect of fertilizers

o Nutrients added by legume crops

o Crop residues left on the ground.

o Crop efficiency in the use of soil and applied nutrients.

1. Soil feeding power: Growing different crops in different seasons changes the nutritional status of the soil,

estimated by soil analysis at the start of the season. The supply power of the soil increases with rotating

legumes.

2. Application of fertilizer and addition of crop residues. Nitrogen and potassium available in the soil after peanuts

are higher than the initial state of the soil. But after pearl millet, only the state of potassium in the soil is improved

and no change in P.

3. Nutrient uptake by crops: The total amount of nutrients taken up by crops in one sequence gives an

indication of the fertilizer requirement of the system. The balance is obtained by subtracting the fertilizer

applied to the crops from the amount of nutrients taken up by the crops.

4. Residual effect of fertilizers: The amount of residue in the soil depends on the type of fertilizer used.

Phosphate fertilizer and FYM have considerable residues in the soil, which is useful for subsequent crops. The

residues left by potassium fertilizers are marginal.

5. Effect of legumes: Legumes add nitrogen to the soil at a rate of 15 to 20 kg / ha. The amount of nitrogen

added depends on the objective. The green gram cultivated for the grain, brings respectively 24 and 30 kg

of nitrogen to the following crop. The inclusion of green legume manure in the system adds 40 kg to 120 kg

N / ha. The availability of phosphorus is also increased by the incorporation of green manure crops. The

availability of potassium for the next crop is also increased by residues from the peanut crop. Crops

Residues add a considerable amount of nutrients to the soil. In legume crops contain a low C: N ratio and

break down quickly to release nutrients.

6. Crop efficiency: Jute is the most nitrogen efficient crop, followed by summer rice, maize, potato, and

groundnuts, in that order. Crops low in phosphorus, jute> potato> peanut> maize. Peanuts are the most

efficient crop for the use of potassium, followed by corn, jute, rice and potato. Fertilizer recommendations

should be based on the growing system

f. Weed management: Weed problems are seen in individual crops, weed movements and the

postponement effect of the weed control method on subsequent crops is usual.

g. Pests and diseases: Pests and diseases infest successive crops more due to continuous cultivation.

The carry-over effect of insecticides is not observed.

h. Harvest: In sequential culture, the culture can be harvested at physiological maturity stage instead of

harvest maturity.

Important clues

Some of the important clues for evaluating cropping systems are as follows

I) Land use efficiency or land use assessment:

The main objective is to use the available resources efficiently. Multiple cropping, which includes both

intercropping and sequencing, has the primary purpose of intensifying crops with the resources available in

a given environment. Several indices have been proposed to compare the efficiency of different multiple

cropping systems depending on land use, and they have been reviewed by Menegay et al. 1978.

1. Multiple Crop Index or Multiple Crop Intensity (MCI):

It was proposed by Dalrymple (1971). This is the ratio between the total area cultivated in a year and the

area of land available for cultivation, expressed as a percentage (sum of the areas planted with different

crops and harvested in the same year divided by the total cultivated area multiplied by 100).

Where, n is the total number of crops, ai is the area occupied by the ith crop and A is the total area

available for

Culture. It is similar to the intensity of cultivation.

Where a1 + a2 + ... + an is the gross cultivated area and A is the net cultivated area.

2. Crop Land Use Index (IUTC):

The Crop Land Use Index (Chuang, 1973) is calculated by summing the products of the land area of each

crop multiplied by the actual duration of that crop divided by the total crop land area multiplied by 365 days

Where, n total number of crops; ai area occupied by the ith crop, di, number of days occupied by the ith

crop was occupied and A = total area of cultivated land available for 365 days.

The CLUI can be expressed as a fraction or as a percentage. This gives an idea of how the land surface

has been used. If the index is 1 (100%), it shows that the land was left fallow and more than 1, indicates

the specification of intercrop and LERais crop. The limitation of the CLUI index is its inability to take into

account the land temporarily available for cultivation by the farmer.

3. Crop Intensity Index (CII):

The Crop Intensity Index assesses the actual land use by farmers as a function of area and time for each

crop or group of crops compared to the total area of available land and time, including land which are

temporarily available for cultivation. It is calculated by adding the product of the area and duration of each

crop divided by the product of the total area of available cropland and the farmers' time periods, plus the

sum of the area of temporarily available land with the time of this land actually cultivated (Menegay et al.

1978). The basic concepts of CLUI and CII are similar. However, the latter offers more flexibility when

combined with a procedure.

Where, Nc = total number of crops grown by a farmer during period T; ai = area occupied by i-th crop

(months during which crop i occupied area ai); ti, duration occupied by the i-th crop (months during which

the crop occupied an area

have) ; T = period studied (generally one year), Aj = total area of cultivated land available to the farmer to

be used during the whole period T; M = total number of fields temporarily available to the farmer to be

cultivated during the period Tj = 1, 2, 3 ........ M, Aj = area of the jth field and Tj = period during which Aj is

available .

CII = 1 means that the land area or resources have been fully utilized and less than 1 indicates an

underutilization of resources.

CII and LER are used to assess the effective growing area.

Crop Intensity / Crop Intensity (CI) indicates the number of times a field is cultivated with crops in a year. It

is calculated by dividing the gross area cultivated by the net area available on the holding, region or

country, multiplied by 100.

When a long-lived crop is grown, the crop stays in the field longer. This is the downside of IC. Time is

therefore not taken into account. So when long duration crops like sugar cane and cotton are grown, the

cultivation intensity will be low.

4. Specific intensity index of crops:

It has been proposed by Menegay et al. 1978. The SCII is a derivative of the CII and determines the area

- the time spent on each crop or group of crops compared to the total time available to farmers.

Where Nk = total number of crops in a specific designation such as vegetable crops or field crops grown by

the farmer during period T; ak = area occupied by the kth crop; tk = duration of the kth culture; AoT, total

area of cultivated land available for use during T. Using this formula, we obtain the market gardening

intensity index, the rice intensity index, the field crop intensity index, etc. .

5. Diversity Index (ID):

It has been suggested by Strought (1975) and Wang and Yu (1975). It measures the multiplicity of crops or

agricultural products that are planted in the same year by calculating the sum
reciprocal of the squares of the share of gross income received from each individual farm enterprise in the same

year.

Where, n = total number of enterprises (crops or agricultural products) and yi = gross income of the ith enterprises

produced during a year.

6. Crop Diversity Index (HDI):

It is calculated using the same equation as the ID, predicts that the value of each farm business is replaced

by the value of each crop.

Yi = gross value of the i th crop planted and harvested during a year.

7. Concurrent Crop Index (ICS):

It is calculated by multiplying the Crop Diversity Index (HDI) by 10,000 and dividing the product by the

Multiple Crop Index (MCI). It is given by Strout, 1975.

8. LERative Crop Intensity Index (IICC):

This is again the modification of the IIC and determines the area and time allocated to a crop or groups of

crops compared to the area - the time actually used for the production of all crops. Numerator RCII equal to

the denominator SCII and the denominator RCII equal to the numerator CII.

These indices can be used to classify farmers, i.e. when the LERative intensity index of vegetable crops is

50%, then the farmer would be considered as a vegetable producer. These indices can be used to measure

transfers of various crops between farms of different sizes and to determine whether consistent types of

cultivation patterns are found in different farm size strata. These indices also make it possible to know how

the area was used for land.

intensively cultivated. But none of these indices take productivity into account and can not be used to

compare different cropping systems and assess their efficiency in using resources other than land.

9. Equivalent crop yield (CEY):

Many crop types / cultures are included in a multiple crop sequence. It is very difficult to compare the

economic product of one culture to another. To cite one example, the yield of rice cannot be compared to

the yield of grains or legumes, etc. In such situations, comparisons can be made on the basis of economic

returns (gross or net returns). The yield of protein and carbohydrate can also be calculated for a valid

comparison. Efforts have also been made to convert the yields of different crops into the equivalent yield of

a single crop, such as the equivalent yield of wheat (Lal and Ray, 1976 and Verma and Modgel,

1983). Verma and Modgel, (1983) developed the equation to calculate the equivalent wheat yield (WEY).

Crop Equivalent Yield (CEY): Yields of different intercrops / crops are converted into equivalent crop yield

of any crop based on the price of the product.

CEY is the equivalent crop yield; Cy is the yield of the main crop, the yield of other crops converted to its

equivalent and Pc is its respective price; C1y, C2y

. . . .crop
. . . .yield
. . . .and
are Pc1
the intercrop / other crop
and Pc2 ............. areyields that are toprices.
their respective be converted to the equivalent of the main

Indices based on the energy approach

Energy efficiency = Energy production (MJ / ha) / Energy input (MJ / ha)

Net energy (MJ / ha) = Energy production (MJ / ha) - Energy input (MJ / ha)

Energy productivity (kg / MJ) = Production (cereals + by-products, kg / ha) / Energy input (MJ / ha)

Energy intensity (in physical times, MJ / ha) = Energy production

(MJ / ha) / Production (cereals + per product, kg / ha)

Energy intensity (in economic terms, MJ / Rs) = Energy production

(MJ / ha) / Cost of cultivation (Rs / ha)

Economic viability

Indications like CEY, LER, RYT etc. give the biological suitability of the culture system to an area. At the

same time, the cultivation system must be economically viable and profitable. The following economic

indications can be used to assess the profitability of the culture system.

1. Gross returns: The total monetary return of economic products such as cereals, tubers, bulbs, fruits,

etc. and by-products (straw, fodder, fuel, etc.) obtained from the crops included in the system and

calculated on the basis of local market prices. The total yield is expressed in terms of unit area, usually one

hectare. The main disadvantage of this calculation is that the market price of the product is higher than that

actually obtained by the farmer. In general, the calculated gross yield is somewhat inflated compared to the

actual revenue obtained by the farmer.

2. Net return or net profit: It is calculated by subtracting the total cost of cultivation from the income. This

value gives the real profit obtained by the farmer. In this type of calculation, only variable costs are taken

into account. Fixed costs such as rent from land, income from land, interest on capital, etc. are not

included. However, for a realistic estimate, the fixed costs should also be included.

3. Return per FCFA invested: This is also called the benefit-cost ratio or the input-output ratio.

This index provides an estimate of the benefit and expense incurred by the farmer in adopting a particular

cropping system. Anything above the value of 2.0 can be considered valid.

4. Yield per day: This is the income per day, which can be obtained by dividing the net yield by the number

of growing days.
This gives the efficiency of the cultivation system in terms of monetary value. If the system spans a year, the

denominator can be replaced by 365 days and the number of days for the whole year can be calculated.

No single index can give a good comparison of different cropping systems. Therefore, several indices are

used together to assess the economic viability of the system.

Land Equivalency Ratio (LER):

This is the most frequently used effective indicator. The LER can be defined as the relative area of land

devoted to the single crop that would be required to produce the equivalent yield in a mixed cropping or

intercropping system at the same management level.

Where La and Lb are the LERs of culture a and culture b, respectively; Yab = relative yield of crop a in

intercrop, Yba = relative yield of crop b in intercrop, Yaa = yield of crop a in pure stand and Ybb = yield of

crop b in pure stand.

A LER greater than 1 indicates a yield advantage, a value of 1 indicates no grain, and a value less than 1

indicates loss of yield. It can be used for both replacement intercrop and additive series.

The LER is the sum of the ratios of intercrop yields to the yield of the pure crop. The LER gives a better

picture of the competitive capacities of the cultures that make it up. It also gives a real yield advantage of

the intercrop. In other words, the LER measures the production efficiency of a different system by grouping

the production in terms of area. The LER gives an accurate assessment of the biological efficiency of

intercrops.

Total relative returns (RYT):

The yield of a crop, expressed as part of the yield of a crop mixture, is the relative yield of the crop, and the

sum of the relative yields of the crops making up the mixture is called the total relative yield (RYT). When

the LER is compared

at a density of uniform overall planting for pure crops and intercrops it is called RYT. In the RYT, the

advantage of yields is to measure not only the unit area, but also the unit population. This method is mainly

used for replacement series.

Coefficient of relative size (K or RCC): It is proposed by de Wit (1960). It is used in intercropping

replacement series. It indicates whether a species or crop, when grown in a mixture, produced more or less

yield than expected in a pure stand. In a 50:50 mixture, the coefficient of relative bulk can be defined as

But when the population differs from 50:50 then,

Where, K = coefficient of each crop species

Yaa = Return of the pure position of a

Ybb = yield of the pure stand of b

Yab = yield of the mixture of a in combination with b

Yba = yield of the mixture of b in combination with a

Zab = seeded proportion of a mixed with b

Zba = sown proportion of b mixed with a

Kab = The values indicate the following conclusions:

K> 1 = there is a yield disadvantage

K = 1 = there is no difference

K <1 = there is a yield advantage in the mixture

The bulkiness factor and LER give the efficiency advantage, but only the LER gives the magnitude of the

advantage.

Therefore, it is best to use the LER to assess the effects of competition and the yield advantage in

intercropping situations.
The two main indicators of dominance are the aggressiveness index and the competition index.

Aggressiveness is proposed by Mc Gihrist (1965). It gives a simple measure of the relative increase in yield

of species A compared to that of species B. It is an index of dominance.

The inoculated proportions of species A and B are represented by ZA and ZB, respectively. An aggressive

value of Zero indicates that the species that compose it are also competitive. A positive sign indicates the

dominant species and a negative sign the dominated species.

The basic process of the competition index is the calculation of two equivalence factors, one for each

constituent species. It is the product of two equivalence factors, one for each constituent species. It is a

measure that allows us to know the yield of various crops, whether they are grown together or separately. It

indicates the yield per plant of the different mixed crops and their respective pure stand on the basis of a

unit area. If the yield of any crop grown together is lower than its respective yield in pure stand, then this is

a bad association, but increased yield means positive benefit. CI is proposed by Donald (1963).

Effective Earth Equivalence Ratio (ELER): Mead and Willey (1980) showed that any required ratio could

be achieved by cultivating the combination of land area and one of the single crops the rest.

The LER is a measure of the net benefits of the combined intercropping, determined by adding the relative

yields of the crop and the monoculture.

Basic Land Equivalency Ratio (SLER): In situations where the primary objective is to produce yields of

one component (staple crop), usually a cereal and some legume yields, the concept of SLER is

compounded.
Where, MDA is derived from the yield of A as a mixture yield and P, the proportion of land devoted to

intercropping. The two yields of the mixed crops are MA and MB and the yields of the monoculture crops

are SA and SB.

Earth Equivalence Coefficient (CET):

It was proposed by Adetilaye and Ezedinma (1986) as the product of the components of intercropping.

It can therefore be considered as a measure of association or interaction when the culture with the strength of

the relationship for a mixture of two cultures, the minimum product expected by the yield advantage is

obtained and the CEL is greater than 0.25 (25%). This was obtained from 50/50 yields where interspecies

competition matched intraspecies competition.

LEC = la * LB = 0.5 * 0.5 = 0.25.

The LEC is developed to assess the interaction and potential of crop mixtures. It is derived from the

understanding that in inter-crop yields, compared to the optimum yield of a single crop, competition is due

assuming that cross-competition is absent.

Surface Harvest Equivalence Report (RER):

It was proposed by Bal Subramanian and Sekayange (1990). It indicates resource efficiency. The concept of

AHER combines area-time factors in a practical sense by quantifying the inter-crop yield advantage,

especially in multi-season.

Crop performance report and its types

It is defined as the productivity of an intercrop per unit of soil area compared to that expected from single

crops sown in the same proportions (Azam Ali et al 1990). For each crop, the productivity of the interlayer

can be expressed as a partial RCP.

Yield advantage in intercropping

Yield is considered a primary consideration in assessing the potential of intercropping practices. In

intercropping of legumes and non-leguminous plants, the yield of non-leguminous plants increased in

intercropping compared to monoculture. Intercropping is found to have made efficient use of land and

improved yield.

Crops are grouped together due to higher yields and greater biological and economic stability of the system. The land

equivalent ration (RET) is the most common index adopted in intercropping to measure land productivity. It is often used as

an indicator to determine the effectiveness of intercropping. RET> 1 indicates greater efficiency of land use in the

intercropping system. It is due to greater efficiency in the use of resources in intercropping or an increase in plant density.

The LER shows the advantage of intercropping cereals and marshmallows. Tsubo et al (2005) reported that intercropping of

legumes and cereals were generally more productive than monoculture. Intercropping generally gave combined yields and

higher cash yields than those obtained with either crop grown alone. The net yield of intercrops of radish and amaranth is

correlated with the planting density of amaranth. Intercropping of pepper and cowpea gave a high net yield compared to

monoculture. The net yield of intercrops of radish and amaranth is correlated with the planting density of amaranth.

Intercropping of pepper and cowpea gave a high net yield compared to monoculture. The net yield of intercrops of radish and

amaranth is correlated with the planting density of amaranth. Intercropping of pepper and cowpea gave a high net yield

compared to monoculture.
UNIT III

Above and below ground interactions and allelopathic effects; competitive relationship; multistage crops

and yield stability in intercropping, role of non-cash inputs and low-cost technologies; need for research on

sustainable agriculture.

Plant interactions and their types

The interaction between the different component cultures: in intensive crops, when crops are grown in

combination (intercropping) or in sequence (sequential crops), there is an interaction between the different

species of component crops, which is essentially a response of one species to the environment as modified

by the presence of another species (commonly referred to as interference or interaction).

Interference can be divided into two

a) Reactions of a plant on its environment and

b) Additive reactions when something is added.

When a factor is removed from the environment, the resulting reaction of neighboring species can be

negative, positive or neutral. Competition between plants is an example of the interaction between the

eliminated factors. Some of these additive interactions are allelopathic and symbiotic. When crops are

grown in sequence, the residual effect of the previous crop influences the next crop; it can be harmful or

helpful. The toxic chemicals (allelopathic chemicals) left in the soil by the roots of the sunflower inhibit the

germination of the next crop. Sorghum stubble with a high C: N ratio causes nitrogen immobilization,

resulting in nitrogen deficiency in the early stages of subsequent crops. The roots of legume crops and their

residues add nitrogen to the soil. Interaction can be 1. Competitive 2. Non-competitive and 3.

Complementary

1. Competitive interaction: - One species may have a greater ability to use the limiting factor and will win

at the expense of the other, this is called competitive interaction or interference. Or, when one or more

growth factors are limiting, the species which is best equipped to use the limiting factor (s) will win at the

expense of the other and this is called a competitive interaction. In mixed culture communities,
if the associated species have to share their growth from a limited set of resources such as light, water or

nutrients, then this is a non-competitive interaction or interference.

2. Non-competitive: - If the crops are grown in combination and the growth of either species is not

affected, this type of interaction is called non-competitive interaction or interference. Or if these resources

(growth factors) are present in sufficient quantity so that the growth of one or another of the species

concerned is not affected, then it is an interaction or a non-competitive interference.

3. Complementary: - If one species is able to help the other, we speak of complementary interaction. Or if

the species that compose it are able to exploit to provide growth factors in different ways (temporal or

spatial) or if one species is able to help the other by providing factors (like legumes which provide a part of

N symbiotically attached to non-legumes), this is a complementary interaction or interference.

Interaction in intercrops: Competition between associated crops in mixed crop communities has been

examined by Donald (1963), Trenbath (1976) and Willey (1979).

Competition for solar radiation:

Solar radiation exceeding 700 nm is called near infrared radiation (NIR). PAR is commonly referred to as

light and is directly related to the photosynthetic rates of crop components, while NIR is the primary source

of energy derived from evapotranspiration, sensible heat exchange, and other photomorphogenic

processes. These two types of radiation are discussed together in this section.

The Beer Law describes the penetration of light into the foliage of a crop if the foliage distribution is uniform

in a horizontal line.

I = Io e- KL

Or

- I is the luminous flux density on a horizontal surface below the units

- L of the leaf area index (LAI),

 - Io is the density of luminous flux on a similar surface above the vegetation cover.

- the base of the natural logarithm and K is the extinction coefficient.

In sparse plant stands or with a low LAI leaf area index, the beer law underestimates light interception. PAR

is directly related to the photosynthesis rate of component crops. Intercropping can increase light

interception by up to 30-40%. The taller crop in intercrop systems intercepts most of the solar radiation

while the shorter component suffers. In some intercropping systems, both crops make efficient use of solar

radiation. If the cultures in the system have different growth times, the maximum light demand occurs at

different times. In these intercrops, there is less competition between component crops and higher solar

radiation is intercepted in the intercropping system than in pure crops. Appropriate choice of crops and

varieties, adjustment of density and planting pattern are the techniques to reduce competition and increase

the efficiency of light use.

1. When one element is higher than the other in an intercropping system, the taller element intercepts more

of the light. Accordingly, the growth rates of the two components will be proportional to the amount of PAR

they intercept, provided that the other growth factors are not limiting and the crops are in their vegetative

phase.

2. The tilt of the leaves greatly influences the amount of light intercepted by the higher component and the

amount available for the shorter components.

3. Ideally, the taller component should have more upright leaves and the shorter component more

horizontal leaves. If these were planted in alternate rows, there would be less competition for light.

In intercropping situations, the component crops are grown so that competition for light is minimized; this

can be achieved by an appropriate choice of crops and genotypes, the shorter components being

harvested early enough that the component harvested later is not too affected.

Evapotranspiration would be much less for the lower part of the plant cover in intercropping, which would

lead to less water stress. Finally, the success of

Intercropping system would strongly depend on the adaptability of the cultures making up the system to the

photoperiod.

Moisture and nutrients: Competition for moisture and nutrients can lead to two types of effects on the

worst performing components.

First, the roots of this component can grow less on the sides towards the aggressive component plants.

Second, plants affected by competition for soil factors may have a higher root-to-seed ratio.

The aggressive component usually absorbs a greater amount of nutrients and moisture from the soil. In the

legume and non-legume combination, the latter absorbs a large amount of P, K and S. Therefore, the

legume may be deficient in these nutrients. However, these effects can be mitigated by applying

appropriate fertilizer. In general, intercropping stands remove more nutrients than stands of single crops.

Other interactions:

Allelopathy: is any direct or indirect harmful effect that one plant has on another through the release of

chemicals or toxins into the root environment.

Some crops may not be suitable for intercropping as they can produce and excrete toxins in the soil, which

are harmful to other components. Allelochemicals produced from the leaves Eucalyptus globulus reduce

considerably germination of the mustard sown below. On the contrary, negative allelopathy, i.e. the

stimulation of the growth of this associated culture by the release of hormone-like substances, is also

possible (Tukey, 1970). The chemical released by a species can inhibit plant species other than the one

that releases it (allo inhibition) or can more strongly inhibit plants of the producing species itself (self

inhibition). Toxic substances can be transformed into active substances by certain microorganisms

(functional allelopathy). The type and amount of allelochemical produced vary depending on the

environment and the genetic makeup of the plant.

Some allelochemicals can be produced by the aerial part of the plant and can reach the soil through

raindrops, falling leaves or insects, which

inhibits the growth of the species below. Allelochemicals produced by the leaves of Eucalyptus globulus greatly

reduced germination of mustard (Brassica spp.) seeds sown below. Many plants exude organic substances

from their roots and some of these root exudates act as allelochemicals inhibiting the growth of neighboring

species. The living roots of the nut ( Juggles nigra), cucumber ( Curcumas sativa) and fishing ( Persia plums) are

known to exude toxic substances that inhibit the growth of plants growing nearby.

Annidation: Annidation is the complementary use of resources by the simultaneous exploitation of

environmental resources in different ways, by the components of a community. Or it is a complementary

interaction that occurs both in space and in time.

a) Announcements in space: The leaf canopies of component crops can occupy different vertical layers

with a higher component tolerating strong light and high evaporation demand and a shorter component

supporting shade and high relative humidity. So one component of culture helps the other. Multistage

cultivation in coconut and planting shade trees in coffee, tea and cocoa plantations use this principle.

Likewise, the root system of the constituent crops harnesses nutrients from different layers of the soil and

therefore uses resources efficiently. Usually,

b) Announcements over time: when two crops of widely varying duration are planted, their maximum light

and nutrient requirements are likely to occur at different times, thus reducing competition. When early

ripening crops are harvested, the condition of late ripening crops can be taken into account so that they can

develop their full vigor. This was observed in the intercropping system sorghum + red gram, peanut + red

gram, and maize + green gram.

c) Another complementary effect in intercropping systems: In an intercropping system, involving

legume and non-legume, some of the nitrogen fixed in the root nodule of the legume may become available

for the non-legume component.

legume. Numerous reports of this beneficial effect of legumes on non-legumes are available in the

literature.

Overall effects of competition

Three main categories of competition can be recognized:

1. The actual yield of each species is lower than expected. This is called mutual inhibition. This

phenomenon is rare.

2. The yield of each species is higher than expected. This is called mutual cooperation. It cannot be

unusual.

3. The yield of one species is lower and the other is higher than expected. This is what we can call

compensation. The species that performs better than expected is considered to have a greater competitive

ability and is called the dominant species. The other species is called the dominated species.

Legume effect: Legumes are widely used for food, fodder, shade, fuel, timber, green manures, and cover crops. Legumes increase the

nitrogen status of the soil through fixation, excretion, or in the absence of an effective nitrogen fixation system. They therefore have a potential

for self-sufficiency in N, the nutrient that most limits productivity. Nutrient self-sufficiency is a desirable characteristic of an agronomically

sustainable cropping system. The inclusion of legumes in intensive cropping systems has many ramifications. They are less demanding on soil

resources, many of them can tolerate a certain amount of shade, fix atmospheric nitrogen in the root nodule, bring part of the nitrogen to the

associated crop and improve soil fertility, able to extract less soluble forms of P and K from the soil, thus making it available for other crops and

also better supplementing valence cations higher like Ca and Mg due to greater CEC of legume roots. But in soils with low K content, they may

be deprived of their due K part, especially when mixed with cereals. Therefore, from the general perspective of maintaining soil fertility and

saving fertilizers, it is beneficial to include legumes in intensive cropping systems. thus making it available for other crops and also better

complementing higher valence cations like Ca and Mg due to greater CEC of legume roots. But in soils with low K content, they may be

deprived of their due K part, especially when mixed with cereals. Therefore, from the general perspective of maintaining soil fertility and saving

fertilizers, it is beneficial to include legumes in intensive cropping systems. thus making it available for other crops and also better

complementing higher valence cations like Ca and Mg due to greater CEC of legume roots. But in soils with low K content, they may be

deprived of their due K part, especially when mixed with cereals. Therefore, from the general perspective of maintaining soil fertility and saving

fertilizers, it is beneficial to include legumes in intensive cropping systems. especially mixed with cereals. Therefore, from the general

perspective of maintaining soil fertility and saving fertilizers, it is beneficial to include legumes in intensive cropping systems. especially mixed with cereals. Therefore,

Interaction in sequential culture:

Competition for light, water, and nutrients, as in mixed crop communities, does not occur when single crops

are grown in sequence. She

only occurs in the Relay crop where there is a short overlap between two crops in a sequence and the

Relais crop experiences a lack of light, especially at the seedling stage. This type of competition can be

minimized by appropriate choice of crops and varieties and by adjusting the time and method of planting.

In intensive multiple crops involving two or more crops in sequence, the main goal is to harvest as much

solar energy per unit area and per unit of time as possible. The important goal of sequential culture is to

increase the use of solar radiation. It is achieved by a longer field duration and rapid soil cover. The crops

are grown one after the other in order to keep the land occupied by the crop for a longer period. In the rice

cultivation system, the efficiency of solar energy use ranges from 1.58 to 2.03% of the PAR in UP The

inclusion of a C4 plant in summer has increased efficiency. If the development of the crop is slow,

In order, the preceding culture has a considerable influence on the following culture, mainly due to

i) Changes in soil condition,

ii) Complementary effect such as the release of N from the residues of the previous crop, in particular from

legumes,

iii) Presence of allelopathic chemicals,

iv) Movement of weeds,

v) temporary immobilization of N due to the high C: N ratio of these residues and

vi) The carry-over effect of fertilizers, pests and diseases.