黄土区长期施用磷肥对冬小麦产量、吸氮特性及土壤肥力的影响

Effects of long-term application of P fertilizer on the yield of winter wheat and characteristic of N absorption and soil fertility in dry-land of Loess Plateau

为了明确长期施用磷肥对冬小麦产量、吸氮特性和土壤肥力的影响,通过21年的黄土高原旱地长期定位肥料试验,测定了冬小麦每株有效小穗数、穗粒数、成穗数、千粒重和干物质量以及植株和土壤中的氮、磷养分含量。结果表明,合理施用磷肥(45～135 kg/hm2)能提高冬小麦穗粒数和千粒重,并能显著提高每株有效小穗数、成穗数和冬小麦抽穗期后干物质累积量,继而显著提高产量,其中当磷肥施用量为135 kg/hm2时,产量最高,为2 869.0kg/hm2,但磷肥施用量过大(达到180 kg/hm2)时,成穗数和抽穗期后干物质累积量显著降低,导致产量显著下降;冬小麦的氮素累积动态呈先增加后下降的趋势,增施磷肥能增加冬小麦吸氮量,但到成熟时,冬小麦地上部分出现氮素损失,损失量达13.4%～44.2%;长期施用磷肥能增加土壤有机质和氮素含量,并显著提高土壤磷素含量,其中全磷含量增加10.7%～64.5%,速效磷含量增加234.6%～667.3%。长期合理施用磷肥,能提高冬小麦产量、吸氮量以及土壤中有机质和氮磷养分含量。

An experiment of 21-year-long-term application of P fertilizer was carried out to study the effects on the yield of winter wheat,characteristic of N absorption and soil fertility in dry-land Loess Plateau. The avail spikelets per spike,grains per spike,spike no. per hm^2 ,1 000 grains yield and the dry matter accumulation of winter wheat were measured, as did the total N, P in both plants and soil. The results showed that the grains per spike and 1 000 grains yield increased, especially the avail spikelets per spike, spike no. per hm^2 and the dry matter accumulation during the period from jointing to filling increased significantly with the application of P fertilizer, so the yield of winter wheat increased significantly. The yield of treatment P3 （135 kg P2O5/hm^2） was higher than that of other treatments,which was 2 869.0 kg/hm^2. But the yield of treatment P4（180 kg P2O5/hm^2） decreased significantly,because of spike no. per hm^2 and the dry matter accumulation during the period from jointing to filling decreasing significantly. The amount of N accumulation of winter wheat increased during the period from jointing to filling, but decreased by 13.4 %-44.2 % after filling. It increased the amount of N absorption with application of P fertilizer. Longterm application of P fertilizer increased soil organic matter and soil N, especially increased soil P significantly. The total P and available P of soil increased by 10.7%-64.5% and 234.6%-667.3% respectively. The yield and amount of N absorption of winter wheat were increased with long-term application of P fertilizer （45-135 kg P2O5/hm^2）.