不同培肥措施对土壤物理性状及无机氮的影响

通过田间动态监测,在东北中部黑土区比较了不同培肥措施下0~60 cm土壤三相比、容重、含水量及无机氮的变化。结果表明,黑土的土壤容重在深松后随着玉米生育进程逐渐向初始状态(1.36~1.54 g cm-3)恢复;与常规栽培(T1)相比,深松+深追肥(T3)和深松+深追肥+增施有机肥(T4)可有效降低玉米成熟期时的土壤容重,改善土壤结构,使20~40 cm层次的土壤三相比接近理想值,T4处理下在成熟期(R6)20~30 cm和30~40 cm土层土壤三相比分别为53.4∶25.2∶21.4和50.9∶25.1∶24.0;此外,T4处理下20~40 cm土壤容重至成熟期时仍保持在1.16~1.29 g cm-3。深松促进了硝态氮的下移,优化了土壤中氮的分配;在开花后,T4处理下20~40 cm土层中硝态氮含量占总含量的31.1%~37.5%,有效的满足了生育后期根系对养分的需求;T4处理下20~50 cm土壤含水量显著提高,较T1处理下平均提高18.0%。研究表明,深松+深追肥+增施有机肥可以改善土壤物理环境,尤其是在20~40 cm,并能显著提升土壤水养库容能力,从而促进养分吸收,提高玉米产量。

Characteristics of Soil Physical Property and Mineral Nitrogen in Different Soil Fertility Managements

A field dynamic monitoring of soil three phrase ratio,soil bulk density,soil moisture content,and mineral nitrogen was conducted at 0-60 cm soil depth under different soil fertility managements in the middle region of Northeast China.The results indicated that soil bulk density returned to the original value (1.36-1.54 g cm-3) with maize growth after subsoiling in black soil.Comparing with traditional cultivation (T1),subsoiling + deep fertilizer (T3) and subsoiling + deep fertilizer + organic fertilizer (T4) treatments significantly reduced soil bulk density and improved soil structure at maize maturity period.And soil three phrase ratios were close to the ideal value in 20-40 cm soil depth.Soil three phrase ratios at 20-30 cm and 30-40 cm soil depth were 53.4 ∶ 25.2 ∶ 21.4 and 50.9 ∶ 25.1 ∶ 24.0,respectively and soil bulk density ranged from 1.16 g cm-3to 1.29 g cm-3 at maturity period in T4 treatments.Besides,the nitrate-N was moved down after subsoiling and the distribution of mineral nitrogen in different soil layers was optimized.There was 31.1％-37.5 ％ of nitrate nitrogen at 20-40 cm in T4 treatment.Soil moisture content in 20-50 cm soil depth was improved significantly by average 18.0％ in T4 treatment compared with in T1 treatment.Soil physical properties were improved and the storage of soil moisture and nutrient in subsoiling + deep fertilizer +organic fertilizer treatment,especially in 20-40 cm,which contributed the nutrient uptake by maize and the high grain yield.