Effect of composts from kiwi crop waste on lettuce growth

Abstract

The process of composting pruning chips and kiwi fruit waste enable these wastes to be recycled as soil organic amendments. However, it is necessary to assess the crop response to the application of these composts. With this aim, a randomized block design pot experiment was set up with the application of composts from pruning chips and kiwi fruit waste mixed in proportions of 2:1, 1:1 e 1:2 (chips:kiwi, w:w). The treatments included: (i) composts with three rates (10, 20 e 40 t ha^-1); (ii) mineral N fertilizer (20.5% N; at the dose of 50 kg ha^-1 N); and (iii) a control treatment without soil amendments. Lettuce fresh weight increased with compost in comparison to mineral N fertilizer application, decreasing the risk of N losses. Lettuce production and N accumulation were higher with soil application of 40 t ha^-1 of compost with 1:2 (chips:kiwi, w:w) due to the greater availability of mineral N in this compost with less chips and the greater amount of mineralized N during the experiment.