水保所知识产出(1956---)知识库

研究不同水分条件下分层施磷对冬小麦根长分布、水分利用效率（water use efficiency，WUE）及产量的
影响，旨在找出旱地农业最佳水肥处理方式。试验设不施磷（CK）、表施磷（surface P, SP）、深施磷（deep P, DP）
和侧深施磷（deep-band P, DBP）4 种处理，每个施磷水平下设补充灌溉（W1）和干旱（整个生育期无补充灌溉）
（W2）2 种水分处理。结果表明，施磷位置及补充灌溉显著（P<0.05）影响冬小麦孕穗期根长分布、WUE 及产
量，同时会改变根系空间分布。干旱胁迫使冬小麦0～<30 cm 土层根长密度下降，降低17.5%，却促进了30 cm
以下土层根长发育，增加13.3%，促进对土壤水分和磷素的吸收，从而提高产量。无论灌溉与否，施磷处理0～
<30 cm 土层根长密度、吸磷量、WUE 及产量均显著高于CK（P<0.05）。施磷位置对冬小麦WUE 和产量的影响
随土壤水分而异，无补充灌溉时，与磷肥表施相比，磷肥深施显著增加WUE 和产量（P<0.05），分别平均增加28.5%
和16.0%，且深层根长（30～100 cm）与吸磷量、WUE 和产量的变化趋势一致；而在补充灌溉时，与磷肥表施相
比，磷肥深施却显著降低WUE（P<0.05），平均降低13.3%，且深层根长与WUE、产量的关系缺乏规律性。该试
验结果表明，土壤水分供应不足时，磷肥深施有利于促进冬小麦深层土壤根系生长发育，提高对土壤水分吸收利
用能力，从而利于形成高产。该研究可为理解作物生长及产量对水分养分空间耦合的响应提供理论依据。

In order to find out the best water-phosphorus (P) application method in improving grain yield and
water use efficiency of winter wheat grown on the semi-arid Loess Plateau of China, this study evaluated the
effects of phosphorus application at different soil depths on root length distribution, water use efficiency and grain
yield of winter wheat under different water condition and analyzed the relationship between root distribution and
grain yield. The experiment consisted of four P treatments and two water treatments in a randomized complete
block design with three replicates. The four phosphorus levels included no P (CK), surface P (SP), deep P (DP)
and deep band P (DBP) and the two water treatments were irrigation (W1) and no irrigation (W2) in the whole
growth period of winter wheat. The results showed that there was large difference in root length distribution,
water use efficiency and grain yield of winter wheat among different treatments. Compared with the irrigation
treatment, the non-irrigation treatment significantly (P<0.05) lowered the surface soil root length (0-30 cm) by
17.5%, but significantly increased (P<0.05) deep soil root length (30-100 cm) by 13.3%, which would be helpful
in promoting the absorption of soil water and P, water use efficiency and grain yield. Root length density was
increased at the site of placement where P was applied under the two water treatments, particularly under water
stress. Whether irrigation or not, P application (SP, DP and DBP) caused the increase of P uptake amount, water
use efficiency and grain yield, compared with the CK treatment. The effect of P placement on water use efficiency
and grain yield of winter wheat was different. Deep P application (DP and DBP) significantly (P<0.05) decreased
water use efficiency of winter wheat compared with SP by 13.3%, while significantly (P<0.05) increased water
use efficiency and grain yield under non-irrigation treatment by 28.5% and 16.0%, respectively. Furthermore, root
length in deep soil layer (30-100 cm) was positively correlated with P uptake amount, grain yield and water use
efficiency under non-irrigation condition，that is, the longer deep soil root length, the better water use efficiency
and higher production under soil drought condition. No correlation was found between root length in deep soil
layer (30-100 cm) and P uptake amount, grain yield and water use efficiency under irrigation condition,
highlighting the importance of well-developed subsoil root system for both high grain yield and water use
efficiency. The study suggested that deep placement of fertilizer phosphorus was a practical and feasible method
of increasing grain yield and water use efficiency under water stress conditions by promoting deep root
development.