MANAGING SOIL FERTILITY AND WATER REQUIREMENTS

Soil

Groundnut is a deep-rooted plant and hence uses both moisture and nutrients from the deeper layers of the soil. Nitrogen requirement in the rain-fed crop is 10–20 kg/ha and in the irrigated crop, 20–40 kg/ha. Phosphorus requirement for the rain-fed crop is 20 to 40 kg/ha and in the irrigated crop, 40 to 90 kg/ha. Although Indian soils are rich in potassium, the recommended dose is 20 to 40 kg/ha both for the rain-fed and the irrigated crop. The application of gypsum at the rate of 500 kg/ha at pegging stage will enhance pod fixation. In virgin lands, when groundnut is newly introduced, the application of a culture of rhizobium as seed treatment is beneficial for increasing nodulation and nitrogen fixation.

Spraying buttermilk 25 and 35 days after sowing fetches good yields. It serves as a growth promoter. Three litres of buttermilk prepared by diluting 1⁄2 litre of curd is sprayed over the crop.

Organic manures Farmyard manure (FYM) and compost are the main organic sources of nutrients for groundnut. Organic matter improves soil structure and reduces compaction and crusting of the soil. It is also required as a source of energy for nodulation and nitrogen fixation by microorganisms. A hard soil may affect pod formation. Adding FYM @ 12.5 tonnes/ha or 4–5 tonnes NADEP/BD/vermicompost helps to get rid of such problems. FYM improves the porosity and structure of the soil and supplies the crop with the required micronutrients. It also helps to get rid of harmful microorganisms in the soil. Besides cow dung, FYM also contains stubbles, stalks and other crop residues. These should be applied well in advance, i.e., 15–30 days before sowing and incorporated into the soil with the help of a country plough or a blade harrow. For a rain-fed crop, 6– 7 tonnes and for an irrigated crop, 12–13 tonnes of farmyard manure should be added. An alternative to FYM is to practise green manuring with crops like sunhemp, daincha and other legumes. Green manuring with sunhemp/sesbania/cowpea can also be attempted. Besides these, soil enrichment through bio enhancers, viz., cow pat pit/BD 500/amrut pani/jeevamrut/panchagavya is also advised. Two to three foliar sprays of BD 501, panchagavya or soil application of amrut pani through irrigation water will promote vigour and improve productivity.

Vermicompost

Amrut Pani

Water

Depending on the soil texture, the frequency of irrigation will vary. However, irrigation must be given during the critical stages of growth like flowering, peg formation and pod development. In areas that receive 50–70 cm of rainfall, 2–3 irrigations should be given. For the rabi crop, 3–4 irrigations are necessary. In case of limited water availability, single irrigation at the time of flowering is compulsory. Irrigation of the plot just before harvesting will make the operation easier.

Updated on : Dec 2014