In many sugarcane growing areas, the productivity of the soils has declined due to intensive cropping and lack of proper soil fertility management practices. The soil productivity can be restored through rationalized integrated nutrient management (INM) involving organic manures, fertilisers and biofertilisers.
Recommended INM practices
Following INM practices are recommended.
Bulky organic manures like farmyard manure, compost and pressmud must be incorporated into the soil at the rate of 15 to 25 t/ha before planting
Sunnhemp green manure can be grown as intercrop and incorporated into the soil around 30 to 45 days after planting.
Soil-test based fertiliser schedules are advisable. When this is not possible, a blanket schedule of 275-65-115 kg of N, P and K can be adopted.
Phosphatic fertilisers, preferably super phosphates can be applied basally or at the time of first hoeing and weeding during 30 to 45 days after planting.
Nitrogenous and potassic fertilisers must be applied in four splits, first split during 30 – 45 days, second split during 60-75 days, third split during 90 – 105 days and fourth split during 120 – 135 days after planting.
The efficiency of urea can be enhanced by blending it with neem cake powder in 4:1 ratio, a day before application. It is advisable to apply the mixture of urea and potash fertiliser in holes of 10 cm depth at intervals of 15 cm spacing on the sides of the plant rows.
Fifty kg of micronutrient mixture/ha made up of 20 kg of ferrous sulphate, 10 kg of manganous sulphate, 10 kg of zinc sulphate, 5 kg of copper sulphate and 5 kg of borax may be applied basally in the planting furrows.
When the chlorotic symptoms due to deficiency of iron or zinc are observed on the leaves of the crop, 5 kg of ferrous sulphate, 2.5 kg of zinc sulphate and 5 kg of urea per hectare may be dissolved in 500 litres of water and sprayed over the foliage. If necessary, one or two more sprayings can be given at intervals of 15 days.
Azospirillum and phosphobacteria biofertilisers at 10 kg each/ha may be mixed with 10 kg of compost and applied basally in the planting furrows or at the time of first hoeing and weeding during 30 – 45 days after planting. The soil pH must be maintained in the neutral range of 6.5 to 7.5 for the crop.