生物质炭与氮肥配施对春小麦产量及其C︰N︰P的影响

Effect of combined application of biochar and N-fertilizer on yield and C∶N∶P ratio of spring wheat

碳(C)、氮(N)、磷(P)生态计量化学为研究作物-土壤生态系统物质循环及其能量流动提供了崭新视角,研究生物质炭配施不同用量氮肥下小麦C、N、P计量特征,可为探明区域养分限制性以及进行合理施肥等提供理论依据。本文通过田间定位试验,测定施50 kg(N)·hm^(-2)氮肥、100 kg(N)·hm^(-2)氮肥、施生物质炭、生物质炭与50 kg(N)·hm^(-2)氮肥配施、生物质炭与100 kg(N)·hm^(-2)氮肥配施等处理下小麦产量、CNP含量及其生态化学计量等指标。结果表明:相比空白对照(不施氮肥和生物质炭)处理,其他不同处理均显著提高了小麦秸秆和籽粒产量,除了单施生物质炭处理,其他处理均不同程度提高了小麦地上部各器官N含量,生物质炭配施不同用量氮肥显著提高了茎秆和籽粒C和P含量。计量比结果表明,相比对照处理,生物质炭和50 kg(N)·hm^(-2)氮肥配施显著降低了叶片C∶N和C∶P,生物质炭和100 kg(N)·hm^(-2)氮肥配施处理则显著降低了茎秆C∶N、C∶P、N∶P以及籽粒C∶N、C∶P。研究区小麦叶片N∶P大多为18~23,因此小麦可能受到P元素的限制。生物质炭配施氮肥显著提高了作物产量,增加了小麦CNP养分含量,降低了植物C∶N、C∶P、N∶P。总体而言,生物质炭配施100 kg(N)·hm^(-2)氮肥施肥措施的综合表现最优。

Carbon(C),nitrogen(N)and phosphorus(P)are the3main elements existing in living organisms.It has long been known that C∶N∶P stoichiometry of consumers and their resources affect both the structure and function of the food web that eventually influence broad-scale processes such as global carbon cycles.The balance of these nutrients can influence plant growth and its stoichiometry in ecosystems.Wheat is one of the most important food crops and wheat production affects global food security.The combined application of biochar and N fertilizer has been reported to be a beneficial agronomic measure,and noted to affect grain yield and C∶N∶P allocation patterns in wheat.In addition,the study of different N fertilizer and biochar on wheat yield,C,N and P contents and their ratio have been closely linked with nutrient limitation and rational fertilization.In this study,we explored the yield and C,N and P contents and their ratios of wheat under different N-fertilizer and biochar treatments(50kg·hm-2N-fertilizer,100kg·hm-2N-fertilizer,biochar,biochar combined with50kg·hm-2N-fertilizer,biochar combined with100kg·hm-2N-fertilizer and no N-fertilizer or biochar as control).The results showed that different treatments significantly increased wheat straw and grain yield,compared with that of control treatment.Except for the single biochar application,other treatments increased N contents of wheat organs.Biochar combined with different doses of N-fertilizer significantly increased C and P contents of both wheat stem and grain.Biochar combined with50kg·hm-2N-fertilizer significantly decreased leaf C∶N and C∶P ratios.Then biochar combined with100kg·hm-2N-fertilizer significantly reduced stem C∶N,C∶P and N∶P ratios and grain C∶N and C∶P ratios.In terms of nutrient limitation,N∶P ratio in wheat leaf in the study area was18-23,wheat may be limited by P element.Biochar combined with N-fertilizer significantly increased wheat yield and CNP nutrient contents.At the same time,it decreased wheat C∶N,C∶P and N∶P ratios.From the above,the comprehensive performance of biochar plus100kg·hm-2N-fertilizer was the best pattern to enhance wheat productivity.