Effects of application of organic matters and of vermiculite in bean-maize-bean rotation

Abstract

Two experiments were performed with dry beans (Phaseolus vulgaris L.) and a dry bean-maize (Zea mays L.) - dry bean rotation to study the effect of incorporation into soil of the following materials: velvet bean (Stizolobium aterrimum Pip. & Trac.) and sunnhemp (Crotalaria juncea L.), sugarcane bagasse, rice straw, town trash compost and vermiculite. The effects of the materials and strains of Rhizobium phaseoli on biological nitrogen fixation in bean was evaluated in an experiment under greenhouse conditions. Velvet bean incorporation produced the most efficient nodulation and the greatest N and dry matter accumulation. Under field conditions, the application of materials with higher N contents did not inhibit nodulation and nitrogenase activity as did the fertilization with 50 kg N/ha. Incorporation of the organic matter was more effective than its application as mulch on bean yield. Incorporation of sunnhemp, where bean was inoculated, increased grain production at the first planting. The residual effect on maize at the second planting was largest in the treatment with velvet bean and N fertilization. At the third planting no residual effect on bean yield was observed.