【作者】 王虎；

【导师】 王旭东；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2006， 硕士

【摘要】 滴灌施肥以其节水省肥、易控制等优点被诸多学者认可,并在国外及我国一些地区应用,但滴灌施肥条件下水分和养分在土壤中运移分布规律的研究却十分有限。本文研究了大田点源滴灌施肥条件下,水分和NH₄⁺ -N、NO₃^- -N、速效磷、速效钾等养分在不同深度土层中的运移分布特征,分析了滴头流量和灌水施肥量二因子对水分和养分运移分布规律的影响,获得以下主要结论。（1）土壤含水量随土层深度和径向距离增大而递减,径向递减率随土层深度增大而减小。随滴头流量增大,滴头周围地表积水区半径增大,水分在土壤中的径向运移距离增大,竖向入渗水量减少。随灌水量增大,水分在土壤中的径向运移距离和竖向入渗深度增大,径向增大较竖向明显。（2）滴灌施肥条件下NH₄⁺ -N运移属于“对流-吸附同步控制”型,滴头流量显著影响NH₄⁺ -N在土壤中的运移和分布。随滴头流量增大,NH₄⁺ -N在土壤中的径向运移距离增大,0～2.5 cm土层滴头径向15 cm范围NH₄⁺ -N平均浓度增大。随灌水施肥量增大,NH₄⁺ -N在土壤中的径向和竖向运移距离增大,0～25 cm土层滴头径向25 cm范围NH₄⁺ -N平均浓度增大。（3）滴灌施肥条件下,NO₃^- -N运移属于“对流控制”型。土壤NO₃^- -N浓度随径向距离增大逐渐减小,随土层深度增大,先逐渐增大再逐渐减小,竖向湿润锋附近有明显NO₃^- -N累积现象。随滴头流量增大,NO₃^- -N在土壤中的径向运移距离增大,0～25 cm土层滴头径向25 cm范围土壤NO₃^- -N浓度增大。随灌水施肥量增大,0～15 cm土层滴头径向15 cm范围NO₃^- -N浓度增大,20～30 cm土层滴头径向30 cm范围NO₃^- -N浓度减小。（4）滴灌施肥条件下速效磷和速效钾在土壤中的运移都属于“对流主导,对流-吸附控制”型,土壤速效磷和速效钾浓度,随土层深度增大而递减,随径向距离增大,呈现先逐渐减小再逐渐增大趋势,在滴头处及湿润锋附近出现浓度相对高值。随滴头流量增大,速效磷竖向运移距离减小,滴头径向30 cm范围0～2.5 cm土层速效磷浓度增大,10～25 cm土层速效磷浓度减小;随灌水施肥量增大,速效磷径向运移距离增大,0～25 cm土层滴头径向30 cm范围速效磷浓度增大。随滴头流量增大,速效钾在土壤中的分布深度有减小趋势,滴头径向30 cm范围,0～10cm土层速效钾浓度增大,15～30 cm土层速效钾浓度减小;随灌水施肥量增大,速效钾径向运移距离增大,竖向变化不明显,0～30 cm土层滴头径向30 cm范围速效钾浓度增大。（5）供试地区推广滴灌施肥,铵态氮,滴头流量以4 L/h为宜,灌水施肥量控制在16 L左右,滴头间距40 cm;硝态氮,滴头流量以2 L/h为宜,灌水施肥量控制在8 L左右,滴头间距50 cm;磷和钾,滴头流量以2 L/h为宜,灌水施肥量控制在8 L左右,滴头间距更多还原

【Abstract】 Drip fertigation technology has been accepted by many scientists for its merits of economy water and fertilization and can be controlled easily. It has been widely applied by some places overseas countries and our country. But the study of water and fertilizer distribution pattern in soil under the condition of drip fertigation is very restricted. The experiment was conducted to investigate the influence of dripping end flow and fertigation volume on the distribution pattern of water and fertilizer in soil, and to analyze the change rules of water NH₄⁺ -N、NO₃^- -N、available phosphate and available potassium in different deep soil layers under the condition of field. And draw thereinafter main conclusions.1、As the radius distances and soil layer depth increased, water content of soil will be lessened, and the rate of level reducer decreased as the soil depth increased. When dripping end flow increased, surface pond radius around drop increased, the moving distance in level of water increased, but the in leakage depth of water in vertical decreased; As irrigation volume increased, moving distances in horizontal and in leakage depths in vertical of water increased, and the change distance in horizontal is more obvious.2、NH₄⁺ -N moving belongs to“convection- adsorption control in step”style, Dripping end flow influenced NH₄⁺ -N moving and distribution obviously in soil. As dripping end flow increased, NH₄⁺ -N moving distance increased in level in soil , NH₄⁺ -N average density increased in level of 15cm and 0～2.5 cm in vertical. As fertigation volume increased, NH₄⁺ -N moving distance in soil increased not only in level but also in vertical, NH₄⁺ -N average density increased in the scope of 25cm in level and 0～25cm in vertical.3、NO₃^- -N moving belongs to“convection control”style. As the level distance increased, NO₃^- -N density decreased, as the soil layer depth increased, NO₃^- -N density increased firstly, and then reduced later, cumulate NO₃^- -N emerged round soil wetness peak in vertical. Dripping end flow increased, NO₃^- -N moving distance in horizontal in soil increased, NO₃^- -N density increased in level of 25 cm and 0～25 cm in vertical in soil. fertigation volume increased, NO₃^- -N average density increased in the scope of 15cm in level and 0～15cm in vertical. NO₃^- -N density decreased in the scope of 30 cm in level and 20～30 cm in vertical.4、Under the condition of drip fertigation, available phosphate and available kalium distribution in soil belong to“convection ruling, convection- adsorption control in step”style, as the soil layer depth increased, available phosphate and available kalium density decreased,更多还原