杂交中稻超多蘖壮秧超稀栽培的养分及干物质积累特性

 以杂交中稻D优95、冈优22为材料，研究了杂交中稻超多蘖壮秧超稀栽培对N、P、K的吸收及干物质的积累、转运和分配。杂交中稻超多蘖壮秧超稀栽培可以明显地提高稻株对N、P、K的吸收及干物质的积累量，尤其是生育后期，超多蘖壮秧超稀栽培对N、P、K的吸收强度仍较大，特别是N素，积累量多，干物质的生产与积累也较常规栽培大而快，表现出明显的后期生长优势；超多蘖壮秧超稀栽培齐穗后穗部N、P、K的积累仍有较大比例靠齐穗后的吸收，且穗部干物质的积累来自于齐穗后的光合作用的比例较大；超多蘖壮秧超稀栽培还可提高N、P、K及干物质在穗部的分配比例，从而提高经济系数及单位N、P、K的生产效率。超多蘖壮秧超稀栽培的本田最佳密度为11.25～15.00万穴/hm2，比常规栽培增产10%以上。

Characters of Accumulation of NPK and Dry Matter of Super-multiple-tiller Seedling Associated with Super-sparse Cultivation in Medium Hybrid Rice

The super-multiple-tiller seedling associated with super-sparse cultivation in medium hybrid rice is a new cultivation method by which the nutritive area of the individual seedling in the nursery bed is 100 cm2 to grow the super-multiple-tiller seedling with over 10 tillers per seedling associated with very sparse transplanting in the paddy field. The characters of accumulation of NPK and dry matter of this new method using rice hybrids Diyou 95 and Gangyou 22 were studied. The super-multiple-tiller seedling associated with super-sparse cultivation obviously promoted the accumulation of NPK and dry matter in the aerial part of the rice plant as its quality of seedlings and growth of plants in the paddy field were much better than those of the traditional cultivation. Much more N, more PK and dry matter were accumulated at the later growth stage by this new cultivation than by traditional one, so the super-multiple-tiller seedling associated with super-sparse cultivation has an obvious later-growing dominance. The requirements of NPK and dry matter for panicle development mainly depended on the transportation from other plant organs after full heading in traditional cultivation. However, the ratio of NPK and dry matter accumulated in the panicles after full heading to which in the whole growth period was much higher in super-multiple-tiller seedling as sociated with super-sparse cultivation than those in the traditional cultivation; therefore the distribution of NPK and dry mptter in the panicles were increased and the harvest index and the production efficlency of NPK were ralsed by the super-multiple-tiller seedling associated with super-sparse cultivation. It was proved that the optimum density in the paddy field of the super-multiple-tiller seedling associated with super-sparse cultivation is 112500 to 150000 hills per hectare. No difference was found between the two rice hydrids with different tillering ability on the results mentioned above.