<b>Nutrient uptake, exportation and use efficiency of upland rice in function of sprinkler irrigation levels</b> - DOI: 10.4025/actasciagron.v25i1.2454

Abstract

A field experiment was carried out on a Typical Haplustox, in Selvíria, MS, Brazil, to evaluate the effects of water levels applied through sprinkler irrigation on plant dry matter, macronutrients uptake at flowering, exportation and nutrient use efficiency of dry land rice, cv. Caiapó. The water levels used were: natural rain and four water levels supplied by sprinkler irrigation. Irrigation levels were based on crop coefficient (Kc) for dry land rice that resulted in water level 2 (L₂). Water levels L_{1,/sub> and L3 were defined as 0.5 and 1.5 Kcs used in L2, respectively, and Kc=1.95 was used on water level 4 (L4) during all plant cycle. The water level 4 (L4) promoted greater nutrient uptake, however the same was not verified in relation to the exportation, because there was not translocation for the grains in the same proportion. The greatest grain yield and nutrient use efficiency was obtained under water level 2 (L2). Efficiency of absorbed nutrients for grain production, showed for the cv. Caiapó, followed the decreasing order: S>P>Mg>Ca>K>N.}