Soil test based nutrient management for short-duration cassava (Manihotesculenta): Analysis of growth, biomass, yield, quality, nutrient uptake and soil nutrient status

Short-duration (6–7 months) cassava (Manihot esculenta Crantz) enables better utilization of resources and crop diversification than the normal duration crop (9–10 months). Field experiments were conducted for three years (2004–2007) at Thiruvananthapuram, Kerala, in a lowland situation akin to rice fallow to standardise nutrient management practices for short-duration cassava. Five short-duration cassava lines (Vellayani Hraswa, Kalpaka, Sree Jaya, Sree Vijaya and triploid 2–18) were evaluated under 4 levels of fertility (12.5 t FYM (100%)+ NPK, 75% FYM + NPK, 50% FYM + NPK and NPK fertilization based on soil test data) in split plot design with 3 replications. ‘Triploid 2–18’ yielded significantly higher fresh tubers (28.45 t/ha) than other four cultivars. The high yielders produced appreciably taller plants and more leaves, higher total and tuber biomass. Nutrient management based on soil test data for organic C, available P and K status along with 12.5 t/FYM, which resulted in the saving of full P, 10% N and 15% K by the third year, promoted plant height, leaf production and nutrient uptake, produced higher tuber yield (24.18 t/ha), tuber and total biomass, dry matter and starch content of tubers besides maintaining organic C, available N, P and K status of the soil, leading to positive nutrient balance.