LPM 121: Fodder Production and Grassland Management (1+1)

AGRONOMIC MEASURES

• Agronomic measures are mostly adopted in dryland areas where slope is gentle i.e. less than 2% when one or more agronomic measures are combined, erosion can be reduced even if the slope is more than 2%.
• Following are the commonly adopted agronomic measures
  • Contour cultivation
  • Tillage
  • Mulching
  • Cropping systems
  • Strip cropping
  • Use of chemical and
  • Others
• Contour cultivation
  • Contour cultivation includes contour ploughing, contour sowing and other intercultural operations. By ploughing and sowing across the slope, each ridge of plough furrow and each row of the crop act as an obstruction to run off and provide more time for water to enter into the soil and reduce soil loss.
• Tillage
  • Conservation tillage is disturbing the soil to minimum extent necessary and leaving crop residues on the soil. Mostly adopted conservation tillage system is zero and minimum tillage, and this can reduce the soil loss to an extent of 50% over conventional tillage.
• Mulching
  • Mulching with plant materials reduces soils loss upto 43 times compared to bare soil and 17 times compared to cropped soil without mulches. Mulches covers more soil surface and protects it from rain drop impact, thus reducing the run off loss. When the crop residues are pressed down into narrow continuous slots of 5 to 10 cm width and 20 to 25 cm depth, the infiltration capacity is increased.
• Cropping systems
  • Pasture land has faced negligible run off and sediment losses. Growing a crop with maximum vegetative cover reduces run off and soil loss. In multiple cropping systems, where the soil is covered with crops throughout the year, the soil loss is minimum as the falling rain drops are interrupted by the crop.
• Strip cropping
  • Strip cropping is a system of crop production in which long and narrow strips of erosion resisting crops (close growing crops) are alternated with strips of erosion permitting crops (erect growing crops) across the slope. Groundnut, moth bean, horsegram, is some of the erosion resistant crops and erosion permitting crops are sorghum, maize and millet.
• Use of chemicals
  • Aggregate stability can be increased by spraying chemicals like polyvinyl alcohol at 480 kg/ha, the rate however depending on the type of soil. Bitumin application also increases the water stable aggregates and infiltration capacity of the soil.
  • Application of organic matter, farmyard manure, crop residues and green manure increases the aggregate stability and thereby reduces the runoff and soil losses.
• Other agronomic practices
  • Application of manures and fertilizers provides early crop cover due to quick growth and thereby reduces the soil loss. Formation of dead furrows with closed ends at 3.6m interval after emergence of the crop sown across the slope, reduces the length of the run off water, hold water and increases the time for infiltration.

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