不同水平氮磷钾对超级稻养分吸收和转运的影响

Effect of different NPK supply levels on nutrient absorption and transport of super rice

以两优培九为材料,研究大田不同氮磷钾养分水平下的超级稻干物质和养分累积特征及转运规律。结果表明:(1)超级稻干物质累积高峰在中期,约累积了总量的50%。干物质累积主要受氮素影响,它们呈现显著的正相关(R=0.8554),磷钾影响不显著。(2)超级稻体内氮磷钾累积有不同的特点,氮磷累积量随超级稻生育期的延长而增加,钾累积在整个生育期表现为单峰曲线。其中氮累积主要集中在前期和中前,约占全累积量的85.4%;磷累积高峰在中期,占总量的58.0%;钾累积量也是中期最高,占累积总量的64.6%。随着氮磷钾施用水平的提高,各自养分累积量均有不同程度的增加,但除氮素与钾素对各自累积量有显著的影响外,磷素及三元素之间互作的影响基本上未达显著水平。(3)超级稻籽粒中,氮磷钾累积量分别为99.2,53.2,23.8 kg/hm2(比例为4.2∶2.2∶1),其中75%氮素、70%磷素、100%钾素来自营养体。氮营养体转运率与氮素水平呈现极显著的负相关(R=0.9610),而不受磷钾明显影响;磷水平的提高有利于磷转运率上升,氮素对磷转运率的影响呈现单峰曲线关系;钾素水平的提高,钾转运率和流失率上升,氮素对钾转运率的影响与磷一样,呈现单峰曲线关系,表明过低或过高的氮素对磷钾累积不利。

Mechanisms of dry matter and nutrient accumulation/transport in super rice （Liangyoupeijiu） planted under different levels of NPK supply were studied. The results showed that： （ 1 ） The maximal value of dry matter accumulation in super rice emerged in the middle growth phase, which was approximately 50% of the total content. Nitrogen（N） supply was positively correlated with the accumulation of dry matter with R value of 0. 8554, however phosphorus（P） and potassium（K） supply had minor effect. （2） Accumulation of N, P and K in super rice had different characteristics. Accumulation of N and P increased with super rice growing; and accumulation of K showed a single-peak curve in the whole growing period. Most of N （85.4%） was accumulated in the early and middle growing stages. Both P and K accumulation reached their maximal levels of 58.0% and 64.6% in the middle growth phase. Nutrient accumulation was positively correlated withthe supply of N, P and K. N and K supply can significantly affected themselves accumulation levels, but the effects of P supply and interaction of N, P and K on nutrient accumulation were not significant. （3） In seeds of super rice, values of accumulated N, P and K contents were 99.2 kg/hm^2, 53.2 kg/hm^2 and 23.8 kg/hm^2, respectively. （ratio： 4.2：2.2： 1）, among which 75% of N, 70% of P and 100% of K came from vegetative mass. Significant negative correlation betwecn N transport rate in vegetative mass and N supply level was observed with R value of 0.9610, while effects of P and K were not significant. Increasing P supply level can enhance P transport rate, and the effect of N on P transport rate showed a single-peak curve. With increasing of K supply, transport rate and lose-rate of K elevated. Effect of N on K transport rate also showed a single-peak curve, which suggested that too high or too low N supply could negatively affect the accumulation of P and K.