Upland rice sowing in conservationist production systems in Vale do Ribeira

Resumo

Vale do Ribeira (Ribeira Valley), region located in the southern of São Paulo State, Brazil, has little more than 30% of agriculturable area, the conservationist systems being promising to optimize the use of the soil and of the agricultural machines. The objective was to evaluate the effective field capacity of a multiple seeder-fertilizer, as well as plant and soil parameters associated with the effects of the machine. The exper­iment was carried out in the Experimental Campus of UNESP, in the Registro County, in the agricultural year 2011/2012, under Cfa humid subtropical climate with hot summer, according to the Köppen classification, with average temperature of 22 °C and annual rainfall of 1400 mm. The experimental area has alluvial soils of the type eutrophic Cambisol. The treatments used were CT (conventional tillage), MT (minimum tillage) and NT (no-tillage). The data collected showed that (1) the highest surface coverage in NT reduced soil temperature at 14 h, as well as the thermal amplitude; (2) the average number of days to seedling emergence was higher in no-tillage, caused by the greater surface coverage and the lower soil temperature in the hottest period of the day; (3) the initial stand of the rice crop was similar in the three tillage systems.

Additional keywords: minimum tillage; no-tillage; seeder; soil temperature.