中文摘要：

在山西闻喜县，通过大田试验，研究了休闲期覆盖增施磷肥（75、112．5、150kg／hm。）对土壤水分、产量形成的影响。结果表明，休闲期覆盖条件下，播种一孕穗期0～100cm土壤蓄水量显著提高，其中播种期显著提高了39～42mm，且越冬一孕穗期土壤蓄水量随施磷量的增加而提高，尤以生育中期效果显著。覆盖后，越冬一孕穗期植株分蘖数、穗数和穗粒数均增加；花后0～30d籽粒灌浆速率提高，花后10d和20-35d千粒质量增加，且穗数、穗粒数、千粒质量均以高磷处理最高。覆盖后，各生育期植株干物质量、产量和经济系数均显著提高，其中产量提高了940～1453kg／hm2，经济系数提高了13％～19％，且增加施磷量植株干物质量和产量也显著提高。覆盖配施磷肥条件下，越冬期40～60cm乖拔节期20～40cm土层蓄水量与穗数关系密切，拔节期和孕穗期60-80cm土层蓄水量与穗粒数关系密切；越冬期0～60cm、拔节期60～100cm、孕穗期60～80cm土层蓄水量与产量关系较密切。旱地小麦休闲期覆盖有利于蓄积休闲期降雨。提高底墒，且蓄水效果可延续至孕穗期；覆盖主要通过提高穗数、穗粒数而实现增产，且以配施磷肥150kg／hm2为宜。

英文摘要：

The field experiments were conducted to study the effects of mulch and phosphorus fertilizer applications （75, 112.5, 150 kg/hm2） in fallow period of dryland wheat on soil moisture and yield formation in Wenxi county of Shanxi province. The results showed that mulch in fallow period improved soil moisture at 0~100 cm from sowing stage to booting stage significantly and soil moisture at sowing stage increased by 39~42 mm. After mulch, soil moisture increased with the increase of phosphorus fertilizer ap- plication from wintering stage to booting stage, especially in middle growth stage. After mulch, tiller number, spike number and grain number per spike from wintering stage to booting stage increased, while filling rate after anthesis for 0~30 d and 1000-grain weight after anthesis for 10 d, 20~35 d increased. Spike number, grain number per spike, 1000-grain weight were the top in high phosphorus treatment. Af- ter mulching, plant dry weight, yield and economic coefficient were all improved significantly, of which yield and economic coefficient increased by 940~1 453 kg/hm2 and 13~19%. Plant dry weight and yield increased significantly with the increase of phosphorus fertilizer application. Under the condition of mulch combined with phosphorus fertilizer, spike number was close relative with soil water storages in 40~60 cm at wintering stage and in 20~40 cm at elongation stage, grain number per spike was close relative with soil water storages in 60~80 cm at elongation and booting stage, and yield was close relative with soil water storages of 0~60 cm at winter stage, 60~100 cm at elongation and 60~-80 cm at booting stage. Mulch in fallow period of dryland wheat was conducive to accumulate rainfall and improve soil basic moisture, and the effect could last to booting stage. Mulch increased yield by improving spike number and grain number per spike, and the effect of mulch combined with application phosphorus fertilizer of 150 kg/hm2 was better.