Potato and Tuber Crops

CTCRI, Trivendrum recommendations:

Central Tuber Crops Research Institute (CTCRI), Trivendrum Recommendations

• A cassava crop producing a yield of 30 t/ha removes 187 kg nitrogen, 33 kg phosphorus and 233 kg potassium per ha. In order to maintain the soil productivity the crop has to be manured adequately.
• For high yielding varieties of cassava, a basal dose of 12.5 tonnes of FYM/compost along with a fertilizer dose of 50 kg nitrogen, 50 kg phosphorus and 50kg potassium is recommended at the time of land preparation.
• When the crop attains 45-60 days after planting, a top dressing of 50 kg nitrogen and 50 kg potassium/ha has to be applied along with the first intercultural operation.
• For short duration varieties of cassava and local types a fertilizer dose of 50:25:50 kg/ha N, P2O5 and K2O is recommended in splits of 25:25:25 kg/ha of N, P2O5 and K2O as basal and 25:25 kg of N and K2O as top dressing.
• Application of manures and fertilizers at the above rate can maintain a proper balance of nutrients in the soil. Moreover, it can also maintain the availability of major, secondary and micronutrients in the soil. Nowadays, farm yard manure is a scarce resource.
• Experiments conducted at CTCRI revealed that green manuring in situ with cowpea and incorporation of residue of the crop itself can be used as alternate sources of FYM.
• In high P soils, P application can be skipped for the first four years, further P at the rate of 25kg P2O5 per ha is enough.
• Soil application of lime at the rate of 1-2 t/ha was found beneficial in terms of yield and quality of tubers in acid soils. Continuous cultivation of cassava leads to deficiency of micronutrients, particularly zinc and in such cases, soil application of Zn at the rate of 1 g/plant (12.5 kg/ha) at the time of planting can maintain its level in the soil and improve tuber yield.