Grain yield and nutrient exportation by rice cultivars sprinkler-irrigated in different sowing dates

The use of appropriate cultivars and sowing date can provide higher grain yield of upland rice, in sprinkler-irrigated system. However, data about nutrient exportation by sprinkler-irrigated rice grains are scarce. The objective of this work was to evaluate the effect of sowing dates on the grain yield and nutrients exportation by grains of upland rice cultivars (IAC 201, IAC 202, Carajás, CNA 7800 e CNA 7801) under sprinkler irrigation. Experiments were carried out in 1995/96 and 1996/97 growing seasons, on a Typic Haplustox, in Selvíria, State of Mato Grosso do Sul, Brazil. The sowings were carried out at the beginning of the second middle of September, October, November, December, January, and February, in each growing season. A randomized complete block design, in a split plot scheme, with four replications was used. Sowing dates affected grain yield and nutrient exportation on it. November sowing reached highest nutrient exportation, because provided highest grain yield. In early sowing (September), the cultivar Carajás presented highest grain yield and nutrient exportation; however, during October to December sowings the cultivar CNA 7801 presented the best results. It is possible sowing in February using the cultivars IAC 201 and Carajás with grain yield higher than 3900 kg ha-1 under sprinkler irrigation system.

Oryza sativa; upland rice; macronutrient; sprinkler irrigation