Effect of Soil Regenerative Practice on Selected Soil Physical Properties and Eggplant (Solanum melongena L.) Yield

Abstract

Living mulches can play a crucial role in the protection of the soil against erosion, as well as biological and chemical degradation. Soil fertility and its physical properties, including soil structure, are of special importance to crops. Soil physical properties are affected, among other factors, by the type of tillage. In order to determine the effect of regenerative practice (living mulches) on soil physical properties, a two-factorial experiment was conducted. The first factor involved white clover and perennial ryegrass as an intercropping of eggplant. The second factor was the living mulches sowing term: three weeks before eggplant planting, at the time of planting and three weeks after eggplant planting. Covering eggplant inter-rows with living mulches reduced eggplant yield and was beneficial to soil structure and improved water resistance of soil aggregates. Perennial ryegrass had a slightly more advantageous effect on yield and improvement of soil physical properties, as compared to white clover. The greater eggplant fruit yield was obtained from vegetable grown without companion plants. The application of living mulches (especially Trifolium repens L.) caused a non-significant decrease in eggplant fruit yield. It was found that limiting the growth of seedlings sown on the first date result in a decrease in marketable fruit yield (on average 14%). A similar result occurred when living mulches were sown on the planting date of eggplants and difference between the yields was 4.3%. The first term of sowing living mulches—three weeks before eggplant planting—no significantly affected the mean weighted diameter of soil aggregate (MWDg), the water stability index (ΔMWD), the index of waterproof index (Wod) and the soil structure index (W). Later sowing terms resulted in the improvement of the majority of the parameters; however, this was not confirmed statistically. Soil with periodic mechanical treatment of inter-rows showed the 3–4% lower values of soil porosity, 3–16% increased compactness, as well as 28–30% lower indices soil structure and 28–30% for water resistance of soil aggregates compared to the living mulches system.