Desempenho agronômico da soja e qualidade do solo sob rotação e sucessão de culturas em plantio direto

Abstract

In an attempt to reduce the environmental impacts of agricultural cultivation and seeking their sustainability, the adoption of management systems such as the Direct Planting System are the way to obtain biologically active soils and, consequently, more productive and resilient soils. The objective was to study the effects of different species in crop rotation and succession systems on the agronomic performance of soybeans and to evaluate soil quality indices under no-tillage. The research was carried out at the Experimental Farm of the Faculty of Agricultural Sciences of UFGD, Dourados, MS and was carried out in the 2021 autumn-winter harvests, ending in the 2022 autumn-winter harvest, totaling one summer harvest and two autumn-winter harvests. winter, being conducted in a randomized block design with eleven treatments and four replications. The treatments corresponded to the sequence of autumn-winter crops in each year: 2021/ fallow; corn; corn/brachiaria; sorghum; brachiaria/buckwheat; Crotalaria ochroleuca/Brachiaria; black oats; Crotalaria ochroleuca/millet/buckwheat/brachiaria; Niger; vetch; forage turnip. 2022/ fallow; corn; corn/brachiaria; sorghum; wheat; safflower; Crotalaria ochroleuca/millet/buckwheat/brachiaria; Crotalaria spectabilis; fodder radish/oats/buckwheat/niger; brachiaria/buckwheat; Crotalaria spectabilis/buckwheat/millet. Soy was sown in the summer in the 2021/2022 harvest. The amount of dry mass of autumn-winter crops was evaluated at the time of soybean harvest: plant height, first pod insertion height, number of branches per plant, number of pods per plant, mass of one thousand grains and productivity, remaining soybean straw, chemical quality and activity levels of β-glucosidase and arylsulfatase enzymes were evaluated. Comparisons of means were performed using the Scott-Knott test at 5% probability. The systems with crop rotation provided higher yields for the soybean crop. In the 2021 and 2022 autumn-winter harvests, both rotation and crop succession systems produced amounts of dry matter below the recommended for the no-tillage system. The enzymes demonstrate that the management practices used in the area over time provided improvements in the chemical and biological quality of the soil.