麦草覆盖条件下施氮水平对旱地梨树生长发育和果实品质的影响

为探明覆草条件下施氮水平对旱地梨树（Pyrus bretschnei deri Rehd.）生长发育和果实品质的影响，设置在全园覆草条件下株施纯氮1 kg（T1）、0.5 kg（T2）、0.25 kg（T3）和不施氮（T4，CK）四种处理，2011年至2012年测定了土壤和叶片养分、树体营养生长和果实产量品质等指标。结果表明，麦草覆盖条件下施氮能显著降低土壤pH值，提高土壤钙、锌含量，明显促进了梨叶片组织结构生长。随着施氮量的增加，梨树新梢生长量、叶面积和百叶重量、叶绿素含量显著提高。不同施氮处理均能提高梨果品产量，T1、T2、T3处理分别比对照提高25.4%、17.0%、11.6%。施氮后梨果实可溶性糖、有机酸含量明显降低，而果实硬度、可溶性固形物、水分含量等品质指标 处理间差异不显著。

Effect of nitrogen rates on pear tree growth and fruit quality under wheat straw mulching in dryland

This study aims to determine the effect of nitrogen application under wheat straw mulching on pear growth and fruit quality in dryland. From 2011 to 2012, the experiment was performed with four nitrogen treatments of different levels, being 1 kg (T1), 0.5 kg (T2) and 0.25 kg (T3) and CK (without nitrogen input). Soil properties and leaf chlorophyll contents, vegetative growth, fruit yield and quality traits were analyzed. The results showed that the different N application reduced soil pH value significantly, improved soil calcium and zinc contents. N applications promoted leaf growth. N fertilizer significantly promoted shoot growth, leaf area and leaf weight and chlorophyll contents, with fruit yield of T1, T2, T3 being 25.4%, 17.0%, and 11.6% higher than that of CK, respectively. N fertilization decreased fruit soluble sugar, organic acid contents significantly. By contrast, quality parameters such as the fruit hardness, soluble solids, water contents were not significantly different anong treatments.