AGRONOMY CALCULATIONS
1. A student, Mr. Adil wants to calculate the amount of N, P 2O5 and K2O for an area of
300 m × 300 m for the production of maize in UPM when the rate of Urea, TSP and
MOP are given 120, 80 and 45 kg/ha, respectively.
2. Calculate the fertilizer requirements (basal as well as top dress) for an area of 7.5 ha of
rice in the form of Urea, SSP, MOP when N, P2O5 and K2O are applied @ 100-20-30
kg/ha. Assume that half of the Urea and entire quantity of SSP and MOP are applied as
basal and remaining half of Urea is top dressed at equal amount at Maximum Tillering
and PI stage.
3. In an experiment a maize field contains 15 weed species and total density of all weed
species is 75 and the density of Echinochloa crusgalli is 50. Calculate the relative
density of Echinochloa crusgalli?
4. In an experiment a researcher takes the total dry weight of weeds in weedy check plot
is 70 g and total dry weight of weeds in herbicide treated plot is 15 g. Calculate the
weed control efficiency of herbicide treated plot.
5. Pendimethalin (Stomp 30 EC) is to be applied at the rate of 1 kg/ha in groundnut as pre-
emergence application. If the amount of water to be mixed is 500 l /ha. Calculate the
amount of Pendimethalin to be required.
6. Glyphosate is to be applied at 3 kg a.i./ha. The herbicide is available as Round up (41%
SL). Calculate the amount of herbicide required to spray in 1 ha of area.
7. Find out the seed requirement for direct seeded rice for sowing 0.75ha from following
observations: Spacing-20×15cm, Germination%- 90, Purity%- 92%, Test weight- 22g
Seeds required for gap filling- 15%
8. Calculate the seed rate of groundnut from following observations: Spacing 25×25cm,
Germination%- 98, Purity%-96, Seed index- 350g, Shelling%- 70.
9. Find out the seed yield and oil yield of mustard from following observations: Spacing-
25×10cm, No. of branches/plant-5, No. of siliqua/branch- 20, No of seeds/siliqua- 23,
Test weight- 3.6g. Area- 2.5ha, Oil content-40%.
10. Calculate the cropping intensity of 10ha farm where land is utilized as follows:
Block Area Season
Kharif Rabi Zade
A 5 Rice Greengram Greengram
B 3 Rice Blackgram -
C 1 Maize Maize Sesamum
D 1 Redgram Cauliflower -
11. Total depth of irrigation applied for wheat crop of 90days base period is 70cm. Find the
duty of water.
12. A rice crop of 5ha area was irrigated 10 times with 5cm water per irrigation. Find out
the total quantity of water applied in cubic metre.
13. Weight of the soil sample with can is 210g, weight of oven dried soil with can is 180g.
Weight of the can is 40g. Find out the moisture content present in soil.
14. Calculate the water requirement of a crop from following observations: Irrigation-
5.0cm, Effective rainfall-6.0cm, Moisture content at root zone (120cm)- (i) At sowing-
35.8cm, (ii) At harvesting- 30.8cm, Upward flux- 1.23cm.
15. After how many days a farmer will have to apply water to the soil if field capacity,
permanent wilting point, apparent density of soil, effective depth of root zone and daily
consumptive use of water are 35%, 15%, 1.20 g/cc–1, 70 cm and 12 mm, respectively.
Let’s assume allowable soil water depletion is 30% of available soil water.
