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采用田间取样与实验室分析相结合的方法,研究了黄土高原坡地密植枣园土壤质地与肥力状况。结果表明,坡地枣园土壤肥力低,氮、磷严重缺乏,钾相对丰富,土壤属于砂壤土,通气性强,保肥、保水性差。0~60 cm土壤有机质含量为1.687~5.002 mg/kg;全氮为0.072~0.316 g/kg;硝酸盐为2.325~16.846 g/kg;铵态氮为1.187~2.146 g/kg,速效磷为0.270~2.480 mg/kg,速效钾为51.9~169.1 mg/kg,并且含量均随剖面向下减少。颗粒组成大部分为粉砂粒,含量一般在65.75%~68.98%;随有机质含量升高,0.25~0.05 mm微团聚体数量呈上升趋势,二者为正相关;<0.05 mm微团聚体含量则逐渐下降,二者呈负相关。黄土高原坡地密植枣园土壤肥力总体水平很低。除了速效钾为中等级外,有机质、全氮、碱解氮、速效磷均为很低等级。
The soil texture and fertility of the densely-planted jujube orchard on the Loess Plateau were studied by field sampling and laboratory analysis. The results showed that the jujube orchard had low soil fertility, serious lack of nitrogen and phosphorus, and relatively rich potassium. The soil belonged to sandy loam with strong aeration and fertilizer retention, and poor water retention. The contents of organic matter in 0 ~ 60 cm soil were 1.687 ~ 5.002 mg / kg, total nitrogen was 0.072 ~ 0.316 g / kg, nitrate was 2.325 ~ 16.846 g / kg, ammonium nitrogen was 1.187 ~ 2.146 g / kg, available phosphorus was 0.270 ~ 2.480 mg / kg, available potassium was 51.9 ~ 169.1 mg / kg, and the content decreased with the profile downward. With the increase of organic matter content, the number of microaggregates of 0.25-0.05 mm is on the rise, and the two are positively correlated. The content of microaggregates of <0.05 mm gradually increases Decline, the two are negatively correlated. The overall soil fertility of the densely placed jujube orchard on the Loess Plateau is very low. In addition to available potassium intermediate level, organic matter, total nitrogen, nitrogen, available phosphorus are very low grade.