绿肥播前施肥和翻压方式对旱地麦田土壤水肥性状的影响

Effects of fertilization before sowing of leguminous green manure and its incorporation methods on soil moisture and nutrient regime of wheat field in Weibei Dryland

通过田间定位试验，研究种植并翻压绿肥3年以后渭北旱原不同施肥处理（不施肥、磷肥 P2O540 kg·hm^-2、豆科绿肥专用肥30kg·hm^-2）和夏季豆科绿肥翻压方式（提前翻压、提前覆盖、播前翻压和不种绿肥-即夏季休闲）对小麦播前和收获期麦田土壤性质的影响。试验结果表明：（1）施豆科专用肥处理和施磷肥处理的绿肥生物量和养分还田量有高于不施肥处理的趋势，其中提前翻压时施专用肥处理与不施肥处理的差异达显著水平。（2）小麦播前翻压绿肥由于有较高的绿肥生物量和养分还田量，从而显著提高了土壤有机质、活性有机质、全氮和速效钾含量，并增加土壤碳库管理指数（CPMI）。（3）夏闲期种植绿肥显著提高了土壤剖面硝态氮的含量，并在160 cm左右的土层有明显的累积峰；绿肥提前翻压处理的土壤硝态氮含量有高于提前覆盖处理的趋势。（4）绿肥翻压方式各处理160 cm以上土层水分含量没有显著差异，与夏季休闲相比，翻压绿肥时160～200 cm土层水分含量有降低的趋势，但只有绿肥提前覆盖土壤0～200 cm储水量显著低于休闲。

The effect of different fertilizers and green manure incorporations on soil properties have been investigated through field experiment in Weibei area .Fertilizer treatments included CK （no fertilizer） ,P （phosphate fertilizer ,P2O5 40kg·hm^-2 ） ,and SF （special fertilizer for leguminous green manure crops ,30 kkg·hm^-2 ） .Green manure incorporation treatments included early incorporation （green manure was incorporated into soil half month before wheat sowing ） ,early mulching （green manure crop was cut and left on the soil surface half month before wheat sowing ,then incorporated into soil before wheat sowing ） ,late incorporation （green manure was incorporated into soil before wheat sowing ） ,and summer fallow （no green manure ） .The results showed that green manure biomass and nutrients returned to soils of SF and P treatments were higher than that of CK .For early incorporation treatment ,green manure biomass and nutrients returned to soils of SF increased significantly compared with CK .The contents of soil organic matter ,active organic matter ,total nitrogen and available potassium of early incorporation treatment were significantly enhanced due to the higher green manure＆amp;nbsp;biomass and nutrients returned to soil compared with summer fallow ,CPMI was significantly increased as well .Incorporation of green manure increased significantly nitrate content in soil profile and a notable accumulation peak appeared at around 160 cm depth of green manure treatments .Early incorporation treatment had higher nitrate content compared to early mulching treatment .No significant difference of soil water content above 160 cm layer emerged between the green manure treatment and summer fallow ,while green manure treatments had lower soil water content in 160～200 cm layer than summer fallow . Early mulching treatment had significantly lower water storage in 0～200 cm depth compared to summer fallow in 2011 .