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通过大田对比试验研究了常规水稻与覆草旱作水稻的产量构成、根系呼吸强度以及断根对产量的影响。结果表明 ,覆草旱作水稻籽粒产量 (5 85 0 .9kg/hm2 )明显低于常规水稻 (6 6 85 .7kg/hm2 ) ,但前者的秸秆产量 (5 735 .5kg/hm2 )高于常规水稻 (5 4 89.5kg/hm2 )。常规水稻实粒占平均单蘖总量的百分数远大于覆草旱作水稻 ,覆草旱作水稻叶、鞘、秕粒的比例大于常规水稻。覆草旱作的根冠比 (0 .116 )显著大于常规水稻 (0 .0 87) ,前者的根系呼吸强度是常规水稻的 2 .7倍。旱作水稻断根后普遍有增产的趋势 ,而常规水稻则有减产的趋势。常规水稻断 1/ 4、2 / 4和 3/ 4根系时 ,平均每穴籽粒产量较不断根的分别下降 2 3%、15 %和 2 0 %。然而 ,旱作条件下 ,断 1/ 4、2 / 4和 3/ 4根系的水稻较全根的分别增产 2 0 %、7%和 3%。由此可见 ,水稻旱作抑制了同化产物向籽粒的转运 ,叶和鞘中积累了较多的同化产物 ;旱作水稻根系冗余生长 ,消耗了大量碳水化合物 ,可能导致水稻籽粒产量下降。
Field experiments were conducted to study the effects of yield and composition, root respiration rate and root-cutting on the yield of conventional rice and grass-covered upland rice. The results showed that the grain yield of dry grassland rice was significantly lower than that of conventional rice (5 85.09 kg / hm2), but the yield of straw (5 735.5 kg / hm2) was higher than that of conventional Rice (54 4 89.5 kg / hm2). The percentage of conventional rice grains in the total single tillers was much larger than that in the dry grass-covered rice. The percentage of leaves, sheaths and grains in the dry grass-covered rice was larger than that in the conventional rice. The root-shoot ratio (0.116) of grass-covered grassland was significantly higher than that of conventional rice (0. 87). The former’s root respiration intensity was 2.7 times that of conventional rice. Drying of rice generally has the tendency of increasing yield after cutting the root, while the conventional rice has the trend of reducing yield. The average grain yield per hole dropped by 23%, 15% and 20%, respectively, when compared with the conventional roots with 1 / 4,2 / 4 and 3/4 roots. However, under dry cultivation conditions, paddy yield of 1/4, 2/4 and 3/4 roots increased 20%, 7% and 3% respectively compared with the total roots. Thus, the dry-farming rice inhibited the transfer of assimilates to grain, and more assimilates were accumulated in leaves and sheaths. The dry-grown rice grew redundantly and consumed large amounts of carbohydrates, which might lead to the decrease of grain yield in rice.