Production potential and economics of sesamum-pulse intercropping in Onattukara tract

Abstract

An experiment entitled "Production potential and economics of sesamum-pulse intercropping in Onattukara tract" was conducted in the summer rice fallows of Rice Research Station, Kayamkulam from February 1998 to August 1998. The study also aims at estimating the residual effect of the intercropping on succeeding crop of rice during virippu season. The experiment was laid out In randomised block design with nine treatments in four replications. The weather condition during the cropping period was congenial for crop growth. The treatments were sole crops of sesamum, blackgram and greengram, intercropping of sesamum with blackgram and greengram in 1: 1, 2: 1 and 3: 1 ratios. The results indicated that sesamum in general, having a tall growing habit was least affected by shade when put under intercropping systems with pulses under different planting ratios. The association of sesamum had lesser adverse effect on legumes and it was proved that legumes can be grown in a compatible manner with sesamum. The sole crops produced significantly higher seed yield than the intercropping systems, in which yield varied due to differences in

2 population. The sole crops recorded the maximum nutrient uptake values due to more drymatter production as compared to intercropping treatments. The bio-economic suitability of the intercropping systems were studied. Higher LER, LEe, Ree, Aggressivity and sesamum equivalent were obtained in sesamum + blackgram in 1: 1 ratio and sesamum + greengram in 2:1 ratios. The results on monetary returns were higher in intercropping systems irrespective of the pulse crops raised, compared to sole crop of sesamum. The highest gross returns, net returns per rupee invested and !. ~ benefit cost ratio were realised from the sole crop of blackgram. Among intercropping systems, sesamum + blackgram in 1: 1 ratio gave higher monetary returns and benefit cost ratio. The maximum monetary advantage based on LER (Rs. 1219 hal ) was obtained when sesamum and blackgram were grown in 1: 1 proportion. The results on energy equivalents were also higher for sole crop of blackgram and sesamum + blackgram in 1: 1 ratio. In general, the soil nutrient status indicated a significant positive buildup of nitrogen and phosphorus. But in case of potassium, the exchangeable potassium was slightly reduced after the experiment. The yield of succeeding rice crop was not significantly influenced by the preceding crops combinations.

3 Thus raising a sole crop of blackgram in the rice fallows of Onattukara tract appears to be more profitable. Under the circumstances, where an intercrop is desired for yield stability, to reduce risk or for yield diversity, raising sesamum and blackgram in 1: 1 proportion can be recommended as an economically viable and biologically sustainable practice for the rice fallows of Onattukara region during the summer season.