Punjab agriculture department is promoting the cultivation of green manure these days as Punjab Agro is providing subsidy on the seed at the rate of Rs 2,000 per quintal, which costs Rs 6,300 per quintal without subsidy.
Green manures are crops grown specifically for maintaining soil fertility and structure.
They are normally incorporated back into the soil, either directly, or after removal and composting.
There are three main varieties of green manure, including Dhaincha, Cowpea, Sunhemp.
Also some crops such as summer moong, mash pulses and guar act as green manure.
Green manure varieties are incorporated into the soil when the crop is 42-56 days old. Pulses crops are incorporated in soil after plucking of beans after 60 days.
Green manure must be leguminous in nature, bear maximum nodules on its roots to fix large amount of atmospheric nitrogen in the soil.
Why is sowing of green manure important in Punjab?
Punjab’s per hectare fertiliser consumption, which is around 244 kg, is one of the highest in the country and is also higher than the national average.
Growing green manure can curtail this consumption to a large extent by 25 to 30% and can save huge input cost for the farmers.
In Punjab, high-intensity agricultural practices are prevalent as farmers take two-three crops in a year, which requires lots of chemical fertilisers such as urea, diammonium phosphate (DAP) etc.
This leads to deficiencies of micronutrients like iron and zinc, especially in the soils where rice is cultivated thus affecting productivity.
In such a situation, green manuring helps improve soil health and enhance the productivity of the crops.
Also, even the PH level of the soil in several parts of the state is more than 8.5 and 9 per cent and green manure is beneficial to maintain it at the required level which is 7 per cent.
Advantages of green manures:
Green manures are crops grown within a rotation for the purposes of:
building soil organic matter and soil structure
supplying nitrogen and other nutrients for a following crop
preventing leaching of soluble nutrients from the soil
providing ground cover to prevent damage to soil structure
bringing crop nutrients up from lower soil profiles
smothering weeds and preventing weed seedling growth