Fertiliser management in cassava- Groundnut intercropping system

Abstract

An experiment was conducted at Agricultural Research Station, Mannuthy, to study the effect of levels of N and time of application of N and K in a cassava- groundnut intercropping system. This 2x2x4 factorial experiment was laid out in randomized Block design with three replications under rainfed conditions. The study revealed that intercropping cassava with groundnut enhanced the growth parameters of cassava at all stages of growth. Yield attributes, yield and total drymatter production of cassava were also increased by intercropping. The quality characters like drymatter starch and crude protein content of tubers were improved by intercropping. Hundred percent recommended dose of N increased the growth, yield and quality over 75 percent of the recommended dose. Among the time of application T3 (15, 75 and 120 DAP) has given the highest tuber yield (21.92t ha-1) followed by T1 (15,60 and 90 DAP) of 21.65 t ha-1. T4 (basal, 60 and 90 DAP) which is the recommended dose recorded the lowest yield of 17.9 t ha-1. A comparatively higher utilization index was obtained with intercropping and higher level of N (75kg ha -1). T1 andT1 and T3 recorded more UI values than T2 and T4. The nutrient content as well as up take in cassava was increased by legume intercropping and higher levels of N. T1 and T3 recorded more nutrient content in different plant parts as compared to T2and T4. The fertility status of the soil was improved by intercropping and levels of N. Yield of ground nut was influenced by higher levels of N. Yield of groundnut was influenced by higher levels of N and time of application of N and K to cassava.T2 and T4 recorded more yield. Nutrient content and up take of bhusa was not influenced by levels of N and time of application of N and K. Maximum LER was seen in sole cassava plot when N and K was given at 15,75 and 120 DAP while in intercropped plot it was highest when N and K were given at 15,60 and 90DAP. Income from cassava cultivation was increased by intercropping with groundnut application of N and K at 15, 75 and 120DAP. Groundnut can be intercropped successfully with cassava under Kerala condition and a substantial quantity (25 per cent) of fertilizer nitrogen required by the main crop could be saved by this practice. For getting better fertilizer use efficiency of applied N and K fertilisers, 1st dose should be applied at 15 DAP of cassava instead of the now recommended basal Dose. Second dose can be extended up to 75 days of planting and the last dose up to 120 DAP so as to coincide with the harvest of the intercrop and the earthing up of cassava.