Assessing the possibility to use legume plants as cover crops or intercrops in organic tomato production to optimize NUE
Organic farming systems rely on environment-friendly practices, such as intercropping, crop rotations, enhancement of soil fertility through biological processes, composting, and biological pest control, while excluding the use of synthetic chemicals. However, in organic agriculture the availability of N to plants depends on mineralization rates of soil organic matter, which are hardly predictable under field conditions. Therefore, timely supply of sufficient amounts of plant-available N is a challenge for organic agriculture. If N is not available to the plants at critical plant developmental stages, the growth and yield may be restricted. Legume crops are capable of providing N to the soil through symbiosis with N2-fixing rhizobacteria. Nevertheless, also in legume crops the timely delivery of plant available N forms may pose a problem, since at the initial cropping stages the proliferation of N2-fixing rhizobacteria results in immobilization rather than in release of plant available inorganic N forms. The use of legumes as cover crops or intercrops in organic cultivations of non-legumes, aiming solely to increase soil fertility, might strongly contribute to achievement of these goals. In view of this background, a greenhouse experiment with organic tomato aiming at assessing the contribution of the legume crop on the nitrogen needs of the tomato crop. In the experiment, cowpea plants were used as cover crops while faba beans as intercrops with beds of tomato spatially separated plants. Using appropriate spacing on beds and pruning tomato plants to two stems contribute to maintaining an appropriate plant density (but lower than in conventional crops), despite the utilization of part of the ground area for cultivation of legumes. The focus of this work was on measures to facilitate the rapid transfer of biologically-fixed N from the legume crop to the following non-legume vegetable crop by testing the efficiency of the system in terms of biological N2-fixation (BNF). The results indicated that the use of legumes as cover crops or intercrops needs further investigation. Add any result in the abstract.
Gatsios, A., Ntatsi, G., Tampakaki, A., Celi, L. and Savvas, D. (2020). Assessing the possibility to use legume plants as cover crops or intercrops in organic tomato production to optimize NUE. Acta Hortic. 1286, 83-90
organic, tomato, cowpea, faba bean, rhizobia, nitrogen