Green manure and organic compost in successive lettuce and carrot production

Alternative practices to the conventional production system improve soil quality and the sustainability of the environment. The objective of this work was to evaluate the effect of green manure in cover associated with the use of organic compost on lettuce and carrot yield in succession. The experimental design used was in randomized blocks and the treatments were represented by different fertilization managements: spontaneous plants, sunn hemp, lablab, sunn hemp + compost, lablab + compost, organic compost, conventional and control (without fertilization and with periodic removal of spontaneous plants). The study was conducted in a succession system between green manure crop and lettuce and carrot crops. Lettuce grown in succession to lablab and sunn hemp with the addition of organic compost produced more fresh weight than unfertilized and equal to or like the conventionally fertilized lettuce. In these crops, lettuce also presented better quality up to 72 h after harvest. The compost added to the sunn hemp increased lettuce production equaling production with conventionally fertilized plants. Fertilization with lablab, lablab + compost and sunn hemp + compost increased the N, P and K concentration in lettuce plants, equaling the conventionally fertilized plants. The production of marketable carrot roots fertilized with lablab, with and without the addition of compost, was equal to the production with conventional fertilization and, in addition, in these crops were also observed the lowest percentages non-marketable. The results show the potential of lablab and sunn hemp organic compost added in successive production systems.