Sustainable system intensification of sesamum (Sesamum indicum) through legume intercropping in sandy loam tract of Kerala

Onattukara sandy loam tract an important agro ecological zone spread over the Karunagapally taluk of Kollam and Karthikapally and Mavelikara taluks of Alappuzha districts of Kerala. The soils are highly permeable, acidic in reaction and are extremely deficient in all the major plant nutrients. Sesamum is mainly grown in Kerala as a sole crop in the summer rice fallows of Onattukara tract. The crop grows in this tract utilizing the residual moisture available in rice fields. The establishment of the crop is often poor resulting in low productivity. Hence an experiment was laid out to find out the suitability of raising pulses as an inter crop in Sesamum and to find out the nutrient status and residual effect of the intercropping. The experiment was laid out in Randomised Block Design with 9 treatments viz Sesamum sole (T ), black gram sole (T ), green gram sole (T ), Sesamum + 1 2 3 Blackgram (1:1) (T ), Sesamum + black gram (2:1) ( T ), Sesamum + black gram (3:1) (T ), Sesamum + green gram (1:1) (T ), 4 5 6 7 Sesamum + green gram (2:1) (T ), Sesamum + green gram (3:1) (T ) with 4 replication. Sesamum being a soil exhausting crop, the 8 9 inclusion of leguminous crops like black gram and green gram may benefit the companion crop through current nitrogen transfer and to the rice crop through the residual effect. The soil test data after the experiment indicated a significant positive build up of nitrogen and phosphorus in all plots except in plots of sole crop of Sesamum. Among intercropping system, Sesamum + Blackgram in 1:1 ratio gave highest monetary returns and biological efficiencies. The results indicated that legume association with Sesamum could increase the total productivity in addition to the enrichment of soil fertility. Thus, in summer rice fallows instead of growing sole crop of Sesamum, intercropping of Sesamum with black gram in 1:1 proportion can be recommended as an economically viable, biologically suitable and sustainable intercropping system.