Soil Management in the Physical Attributes and the Wheat Crop Irrigated Productivity

Abstract

The objective of this work was the influence of three management systems on the physical attributes and productivity of irrigated wheat, cultivar BRS-254, in the city of Tangará da Serra, MT, Brazil. The experimental design was a randomized block design in split plots, with eight replications, being considered as plots the three systems of soil management: Conventional management (MC) with two gradations (one heavy and one light); minimum management (MM) with light harrowing; and direct seeding (SD). As a subplot: two layers of soil (0 to 10 cm and 10 to 20 cm) and two seasons, being at 42 and 97 days after sowing (DAS) of wheat. The soil physical attributes evaluated were: macro and microporosity, total porosity, soil density and soil resistance to penetration. The yield of wheat crop was also evaluated. For the effects of MC, MM and SD, of the soil layers and DAS in the parameters macroporosity, microporosity and total soil porosity the MC and MM provided higher values ​​of macroporosity and microporosity decrease at 42 DAS. The macroporosity was higher in the layer up to 10 cm and the microporosity in the 20 cm layer at both the 42 and the 97 DAS. The aeration capacity of the soil followed in ascending order in the management systems SD <MC <MM. In SD there was a significant increase in macroporosity from 42 to 97 DAS. Microporosity presented higher value at 97 DAS. Total porosity, as well as macroporosity, presented the highest value at 42 DAS. For the effects on soil density at 42 DAS it was observed that the lowest density value was found in the MM followed by MC. At 97 DAS, the density values ​​practically returned to the initial value before the management intervention. It was verified that the soil density at the end of the crop cycle had an average value around 1.02 kg dm3. At 42 and 97 DAS the lowest soil density value was found in the 0 to 10 cm layer. In the 10 to 20 cm layer at 42 DAS, the SD had the highest soil density value in relation to the treatments studied, but at 97 DAS the SD had the lowest density value. For the effects on soil penetration resistance it was observed that soil resistance to penetration between MM and MC always remained below 2 MPa. The resistance curve showed that the soil rotation was efficient up to 10 cm depth, as they presented values ​​lower than those found for SD, which presented resistance values ​​between 1.5 and 2 MPa. For the effects on yield of irrigated wheat, the use of MM and SD as a way to reduce soil compaction did not contribute to the increase of yield of irrigated wheat. The MC provided higher productivity.