摘要
采用池栽法对春小麦 /春玉米间套系统在不同水分调亏水平下 ,水、肥与根系的时空协调性进行了研究。试验得出 :在小麦拔节后期 (玉米苗期 )以土壤相对含水率 (SRW)的 5 0 %进行亏缺灌水 ,可明显提高间作系统总的生产力 ;间作农田土壤速效磷 (Olsen- P)与根密度的垂直分布呈明显递减特性 ,30 %以上的 Olsen- P和 4 0 %以上的根干重分布在 0～ 10 cm土层 ,而表层含水率常低于 10 % ,水分空间分布与根系和 Olsen- P的错位 ,限制了磷素养分肥效的发挥 ,通过磷肥深施 (2 0 cm土层以下 )和玉米苗期的适度调亏灌溉 ,可促进根系在土壤下层的分布 ,便于深层根系在中、后期对养分的吸收。速效氮在空间的分布受灌溉的影响很大 ,生育前期速效氮虽然在表层含量较高 ,但随生育期的推进 ,逐渐向下层运移 ,因此灌溉农田过量施氮或施法不当 ,将造成氮素随水流失 ,降低氮肥利用效率。
Determining coordinating of Root Water Fertilizer relation was studied. Two crops of spring wheat and spring corn intercropped were grown in cement pool with length of 1 m, width of 1 m and depth of 1.5 m. The regulated deficit irrigations (RDI) of 30%, 50% and 70% of soil relative water content(SRW) were performed at later jointing stages for spring wheat(seedling stages for corn). Total seed yield of intercropping system was increased with 50% of SRW under 50% RDI at seedling stages for corn intercropped. The vertical distribution of soil Olsen P and root weight decreased significantly from surface soil layers to deep layers, above 30% of Olsen P and 40% of root dry mass in 0～100 cm soil depths were distributed in 0～10 cm soil layer, but where the water content is always below 10%, so un coordination of soil water with root and soil Olsen P in soil layers reduced nutrition use efficiency(NUE). RDI and deep P supply increased amount of roots of below 40 cm soil depths, which was favorable to absorb nutrient for roots in deeper soil profile at the middle and later growth stage. Spatial distribution of NO - 3 N and NH + 4 N were influenced by irrigation, at the first period of growth, NO - 3 N and NH + 4 N mainly distributed on the 0～10 cm soil layer, but which gradually moved to deep soil along with crop growth, therefore, nitrogen fertilizer should not be applied at deep soil layer, and should be supplied with several times.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2002年第1期53-56,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
中华农业科教基金资助项目 (99-0 3 -B-9)
国家自然科学基金资助项目 (3 970 0 0 88)
关键词
调亏灌溉
春小麦
春玉米
根-水-肥协调性
间作
套作
时空变异
regulated deficit irrigation (RDI)
spring wheat spring corn intercropping system
root water fertilizer relation
