农田施用水葫芦对水稻干物质生产与分配的影响

Effects of Hyacinth Mulching on Dry Matter Production and Distribution of Rice(Oryza sativa L.)

为促进农田养分循环利用和农业生态环境健康，以粳稻品种运2645为供试材料，设计农田施用水葫芦（将晒干水葫芦按4500kghm^-2农田施用）和不施用水葫芦处理（对照），施N量为120kghm^-2（LN）、240kghm^-2（NN），研究其对水稻物质生产与分配的影响．结果表明：1）农田施用水葫芦使水稻移栽～分蘖中期、分蘖中期～拔节期、拔节～抽穗期、抽穗期～穗后20d和穗后20d～成熟期平均分别比对照8．6％、9．8％、12．2％、15．9％和3．1％，使得成熟期生物产量显著增加（＋9．0％）；2）与干物质生产量相似，水稻平均叶面积指数（LAI）和净同化率（NAR）对水葫芦处理的响应呈相似的季节性变化趋势，但NAR在穗后20d～成熟期有所下降；3）农田施用水葫芦对水稻不同生育时期叶片、茎鞘和稻穗占地上部干重的比例影响不大；4）增加施N量能够明显增加水稻的干物质生产量；水葫芦xN的互作效应对水稻干物质生产与分配无明显影响．5）农田施用水葫芦使水稻生育前、中期干物质生产量增幅较大，对生育后期影响相对较小．

The effects of hyacinth mulching on dry matter （DM） production and distribution of rice were investigated by a field experiment in 2009 to promote farmland nutrient recycling and agricultural ecosystem health. Cultivar Yun 2645 was selected as plant material, and the experiment groups included hyacinth mulching and without hyacinth mulching, and two different levels of N were applied： low N （LN, 120 kg hm^-2） and normal N （NN, 240 kg hm^-2）. The results showed that： 1） The DM production of rice under hyacinth mulching treatment significantly increased by 8.6%, 9.8%, 12.2%, 15.9% and 3.1% during the rice growth periods from transplanting to mid-tillering, mid-tillering to jointing, jointing to heading, heading to 20 d after heading and 20 d after heading to grain maturity, respectively. As a result, the total biomass at maturity increased by 9.0% on average. 2） In general, the seasonal response of crop growth to hyacinth mulching in both leaf area index （LAI） and net assimilation rate （NAR） followed a similar pattern to that of the DM production, except the NAR slightly decreased at 20 d after heading to grain maturity. 3） The weights of leaves, stems and spikes in proportion to the total above-ground DM were no obvious differences with and without hyacinth mulching over the season. 4） The DM production obviously increased with N application increaseing, and there was no interaction between hyacinth mulching and N application observed for the DM production and distribution at majority growth stages. 5） The DM production significantly increased by hyacinth mulching treatment at the early and middle growth stages, whereas little change was observed at the late gro;vth stages. Fig 5, Tab 3, Ref 15