Since early 1980’s, upland rice research agenda in Brazil has been aimed to generate knowledge and develop technologies, targeting the climatically favored regions of the Brazilian savannas. Savanna micro-regions have been classified according to the degree of climatic risk and crop financing policies take in consideration research recommendations. Nowadays, the crop has migrated to these favorable areas. Moreover, the national upland rice breeding program has made an important advance, developing new varities, indica versus tropical japonica derivatives, possessing high yield potential and superior grain quality. These varities, known under the denomination of “aerobic rice”, are specially suited for the Central-North region of Mato Grosso Sate, whose average yield has been steadily increasing. The main roles of aerobic rice in the Brazilian savannas are: 1) pioneer crop in land opening; 2) supplementary irrigated crop; 3) pasture consorciated crop; 4) rotation crop, under no tillage. Although the pioneer crop role is still dominant, yields have been consistently increased by adequate management. Rice supplementary irrigation system has been addressed in the 80 decade, but cultivated area has not evolved, because the prevalent traditional plant type (tropical japonica) did not respond well to irrigation and fertilization practices. Nowadays, the new aerobic varities, of high yield potential, make the system feasible. The rice and pasture consortiation systems, Barreirão and Santa Fe, aimed to renew degraded pasture, have a enornous potential in the Brazilian savannas. But the main challenge in the present research agenda, is to insert aerobic rice as a regular component of grain cropping systems, in succession to soybeans, the leading crop in Brazilin savannas. Among the difficulties of competing with a cash crop, there is, additionally, the problem of adapting rice to the predominant soil preparation for soybean, which is the minimum tillage, or no tillage. These novel systems are described and its potential analised in this paper.
作 者:Beatriz da Silveira Pinheiro, João Kluthcousky, Cleber Morais Guimarães, Luis Fernando Stone
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作者单位:Embrapa Arroz e Feijão, Brasil;
论文来源:水稻可持续生产——政策、技术与推广国际会议(中国杭州,2004年)。
(浏览次数:2010)
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