Agronomy Module 3

Cropping Systems & Practices

1. Rice-wheat system is the dominant cropping system in Indo-Gangetic Plains.
2. Maize-legume intercropping improves soil nitrogen and land use efficiency.
3. Relay cropping reduces risk of crop failure and ensures continuous production.
4. Mixed cropping increases crop diversity and reduces pest incidence.
5. Crop rotation breaks the life cycle of pests and diseases.
6. Zero tillage saves time, labor, and preserves soil moisture.
7. Raised beds improve drainage and root aeration in heavy soils.
8. Contour farming reduces soil erosion on slopes.
9. Strip cropping prevents wind and water erosion.
10. Alley cropping combines trees and crops for sustainable farming.

Soil Management

1. Sandy soil has low water and nutrient retention.
2. Clay soil has high nutrient retention but poor drainage.
3. Loam soil is ideal for most crops.
4. Acid soils can be corrected by liming.
5. Saline soils are reclaimed by leaching with good quality water.
6. Organic matter improves soil structure and water-holding capacity.
7. Green manures improve nitrogen content and soil fertility.
8. Crop residues prevent soil erosion and conserve moisture.
9. Conservation tillage preserves soil structure and organic matter.
10. Deep plowing improves root penetration and soil aeration.

Weed Management

1. Weeds reduce crop yield by 10–50% if uncontrolled.
2. Pre-emergence herbicides act before weed emergence.
3. Post-emergence herbicides act after weeds emerge.
4. Manual weeding is labour-intensive but eco-friendly.
5. Mulching suppresses weed growth naturally.
6. Allelopathic crops like sorghum and sunflower suppress weeds.
7. Integrated Weed Management combines mechanical, chemical, and cultural methods.
8. Echinochloa crus-galli is a major weed of rice.
9. Parthenium hysterophorus is a highly invasive noxious weed.
10. Herbicides must be applied at recommended dose to avoid crop injury.

Harvesting & Post-Harvest

1. Harvesting at proper moisture content ensures seed quality.
2. Threshing separates grain from straw.
3. Winnowing separates chaff from grains.
4. Silage is made from green fodder to feed livestock.
5. Ratooning saves cost and time in sugarcane.
6. Proper storage prevents seed deterioration and pest attack.
7. Sun-drying reduces grain moisture and prolongs shelf life.
8. Cold storage is used for vegetables, fruits, and tubers.
9. Mechanical harvesting reduces labour cost and crop loss.
10. Grading ensures uniform quality for market.

Miscellaneous / Important Facts

1. Harvest index = Economic yield ÷ Biological yield.
2. Horticultural crops include fruits, vegetables, spices, flowers, and plantation crops.
3. High-yielding varieties developed through hybridization and plant breeding.
4. Crop stand uniformity depends on seed quality and sowing method.
5. Plant density affects light interception, growth, and yield.
6. Intercropping increases resource-use efficiency and reduces risk.
7. Cover crops prevent soil erosion and nutrient leaching.
8. Crop residues improve soil organic carbon.
9. Zero-tillage reduces soil erosion and conserves moisture.
10. Organic farming emphasizes biological inputs and sustainability.