水肥耦合对玉米化学计量学特征及其生长性状的影响

为了探讨不同水肥条件下玉米C、N、P化学计量学特征及其影响因素,设置土壤不同含水量和全氮含量的盆栽试验,分析了不同水肥对玉米生长性状和碳氮磷化学计量学特征的影响,并对两者进行了相关分析。试验设置田间持水量的90%,70%,50%(W1、W2、W3),田间正常施氮量的150%,100%,50%,(N1、N2、N3),共9个处理。结果表明:玉米根、茎、叶不同器官干物质量均随着施氮量的减少而减少,随着土壤含水量的增加而增加。高、中水分时玉米株高随着施氮量的增加而增加,当玉米处于干旱胁迫时施氮量对玉米株高影响不大。低水分下的茎粗显著低于高、中水分。玉米根、茎、叶的C含量差异不显著。低氮施肥处理下玉米根、茎和叶的N含量均显著低于中、高氮处理,而后两者对根、茎和叶的N含量的影响表现不一,其中对茎氮含量差异达到显著水平,对叶氮含量在抽雄期以后才显著。玉米C∶N∶P生态化学计量特征随水肥因素的变化表现不一,其中N/P平均为6.01,随着施氮量的增加而升高,随土壤含水量的增加而降低;C/N为0.31,随着施氮量的增加而降低,对水分因素不敏感;C/P为1.62,表现出强烈的内稳性,不随外界生物与非生物环境的变化而变化。

Effects of Water and Fertilizer Coupling on the Stoichiometry Characteristics and Growth Traits of Maize

In order to explore stoichiometry characteristics of carbon, nitrogen and phosphorus in maize and influencing factors under different water and fertilization conditions, pot experiments with different soil water contents and total nitrogen contents were conducted, and the effects of different treatments on maize growth traits and stoichiometry characteristics of carbon, nitrogen and phosphorus were discussed, meanwhile the correlation analysis was carried out. Three moisture gradients including 90% (W1), 70% (W2) and 50% (W3) of field capacity, respectively, three nitrogen levels (150% (N1), 100% (N2) and 50% (N3) of normal nitrogen application in the field, respectively) were set up, and there were nine treatments in the experiment. The results showed that the dry biomass of maize root, stem and leaf diminished as the decreasing of nitrogen amount, increased with the increasing of soil moisture content. When the soil moisture was in high and middle level, plant height of maize increased with the increasing of nitrogen application rate. When maize was under drought stress, nitrogen application rate had little effect on plant height. Stem diameter under low moisture was significantly lower than those under high and medium moisture. There was no significant difference in carbon content among maize root, stem and leaf. Nitrogen contents of maize root, stem and leaf in N3 treatment were significantly lower than those in other two treatments. N1 and N2 treatments had different effects on nitrogen content of maize root, stem and leaf. The difference of stem nitrogen content reached significant level, while the difference in leaf nitrogen content was significant after tasseling stage. The ecological stoichiometric characteristics of C/N: P were different with the change of water and fertilizer, in which the average nitrogen and phosphorus ratio (N/P) was 6.01, and it increased with the increasing of nitrogen application, decreased with the increasing of soil water content. Carbon and nitrogen ratio (C/N) was 0.31, and decreased with the increasing of nitrogen application, but it was not sensitive to moisture factor. Carbon and phosphorus ratio (C/P) was 1.62, which showed strong stability, and did not change with the change of external biological and abiotic environment.