Intercropping studies with annual crops

This pape r tries to illustrate how beneficial interactions between crops can be exploited to increase the overall output of a cropping system. Growth studies with sorghum/pigeonpea and mil let /groundnut a re described to show how intercropping systems can achieve much larger yields than sole crops by using environmental resources more fully over t ime or more efficiently in space. D a t a from moisture stress studies are presen ted to i l lustrate that these advantages of intercropping can be even grea ter unde r stress condi t ions. Possible nitrogen benefits from legumes in intercropping systems are discussed with part icular reference to a study on maize/groundnut . W e e d , pest and disease control are considered and some effects of a sorghum intercrop on the incidence of pod borer and wilt disease in pigeonpea are described. Evidence for improved yield stability in intercropping systems is provided from a review of 94 exper iments on sorghum/pigeonpea. I t is emphas ized tha t in tercropping is especially beneficial to the small farmer in the low-input/high-risk envi ronment of the developing areas of the world but some brief comment s are m a d e on its applicability in more developed condit ions. 1983 Better crops for food. Pitman Books, London (Ciba Foundation symposium 97)