不同施氮量下南方红壤花生农艺性状、产量及土壤养分的变化

为探讨南方红壤旱地不同施氮量下花生农艺性状、产量和土壤养分的变化,采用田间随机区组试验,以高含氮肥料为材料,设置8个处理:不施氮肥（N₀）、200%施氮量（N_200%）、150%施氮量（N_150%）、100%施氮量（N_100%,纯施氮180.48 kg/hm²）、80%施氮量（N_80%）、60%施氮量（N_60%）、40%施氮量（N_40%）和20%施氮量（N_20%）。结果表明:与N₀处理相比,施氮肥提高了花生荚果产量,增产幅度为12.94%~24.62%;荚果产量、单株果重和饱果率随施氮量的增加而增加;而分枝数和百仁重随施氮量变化不明显;株高和百果重以N_80%效果最佳。土壤碱解氮随施氮量的增加而增加。相关分析结果表明,花生荚果产量与饱果率、有机质和碱解氮呈显著正相关;碱解氮与饱果率和有机质呈显著正相关,而与pH呈显著负相关。由主成分分析结果可知,第1主成分性状,即产量因子,如荚果产量、单株果重和百果重对花生生长有重要的作用。通径分析结果表明,百果重和饱果率通径系数较大,所以在提高花生荚果产量中应重视这2个性状。综上所述,从花生产量、农艺性状和成本考虑,以N_80%处理（纯施氮144.38 kg/hm²）的荚果产量、株高、单株果重、百果重、百仁重表现最佳。

Changes of Agronomic Traits,Yield and Soil Nutrient of Red Soil in Southern China under Different Nitrogen Application Rates

To explore the changes of agronomic traits, yield and soil nutrient of peanut under different nitrogen application rates in dryland of red soil in southern China, a randomized block experiment was conducted in the field. Using high-nitrogen fertilizer as the material, eight treatments including no nitrogen fertilizer (N₀), 200% nitrogen application rate (N_200%), 150% nitrogen application rate (N_150%), 100% nitrogen application rate (N_100%), 80% nitrogen application rate (N_80%), 60% nitrogen application rate (N_60%), 40% nitrogen application rate (N_40%) and 20% nitrogen application rate (N_20%) were set. The results showed that compared with N₀, the application of nitrogen fertilizer could increase the yield of peanut pods, and the yield increase of peanut pods was 12.94%-24.62%. Pods yield, pods weight per plant and plump rate of peanut increased with the increase of nitrogen application rate. Branch number per plant and 100-kernel weight did not change significantly with nitrogen application rates. Plant height and 100-pod weight were the best in N_80%. The soil alkaline nitrogen increased with the increase of nitrogen application rate. Correlation analysis showed that there was a significant positive correlation between pods yield of peanuts and plump rate, organic matter, alkaline nitrogen. There was a significant positive correlation between soil alkaline nitrogen and plump rate, organic matter, but a significant negative correlation with pH. Principal component analysis showed that the first principal component trait, the yield factor, such as fruit yield, pods weight per plant and fruit weight had an important effect on peanut growth. Path analysis showed that the path-coefficient of 100-pod weight and plump rate was large, and the two traits should be emphasized in increasing the yield of peanut fruit. In summary, pod yield, plant height, pods weight per plant, 100-pod weight and 100-kernel weight of N_80% were the best in peanut yield, agronomic traits and cost.