旱稻矿质养分吸收与施肥效应

 早稻和水稻的养分吸收规律不同。施氮肥可明显提高旱稻产量,并促进养分吸收;豆科植物与旱稻间套作会增加早稻的氮素养分吸收,对提高早稻产量有重要作用。热带酸性土壤缺磷是限制早稻产量的主要因素之一,施磷肥有显著的增产效果。早稻主要吸收Mehlich-1法浸提形态的磷,但基因型之间对磷的利用效率有明显差异。酸性土壤施入石灰能改善磷的有效性,促进旱稻对磷、钙和镁的吸收而提高产量;但石灰量的增加导致旱稻对钾、锌、铜、锰和铁的吸收减少。旱稻钾的营养和施肥研究结论不一,与各地土壤有效钾含量不同有关。其它元素中锌和硅的研究较多,硅肥和锌肥能提高旱稻产量。我国对旱稻矿质营养及施肥研究仍未引起重视,尤其对国内培育的新品种矿质营养的研究和当前旱稻的主栽区北方碱性土壤中旱稻对氮、磷、钾吸收利用的研究更为薄弱。

Mineral Nutrition Uptake and Fertilization Effects of Upland Rice

Mineral nutrient uptake and fertilization effects of upland rice was studied. Significant differences in nutrient uptake were found between lowland and upland rice. Nitrogen (N) was obviously improved the yield of upland rice and promoted other nutrient uptake. Intercropping legumes with upland rice enhanced N uptake and its yield. In tropical acid soils, phosphorus (P) is one of the most important factors limiting upland rice yield, since P fertilizer applied into the soils resulted in increase in the yield of upland rice significantly. Mehlich-1 P was found a main pool in soil for upland rice uptake, and P use efficiency was distinctly different between upland rice genotypes. Lime amendment in the acid soil improved P availability and promoted absorption of P, calcium, and magnesium, leading to increase in yield. However, excessive lime also reduced absorption of potassium (K), zinc (Zn), copper, manganese and Fe for upland rice. Effects of K amendment on yield of uplang rice were equivocal, resulting from great variations in K availability in different soils probably. Among the other nutrients, Zn and silicon (Si) were the elements taken the most attentions and Zn-and Si-fertilizers improved the yield of upland rice in most cases. The research on the nutrient uptake and fertilization of upland rice has not been paid attention in China, especially on new varieties cropped in the North with alkali soils which is the largest and most potential area of upland rice in the country.