茶园施肥方法探讨

茶园施肥是茶园获得高产的重要途径之一。基于此,通过长期生产实践,根据茶树的不同生育期,结合生产要求,对施肥方法、施肥时间、施肥量和用肥品种进行了探讨,以期更科学地施肥,在生产上有一定的借鉴作用。

Effects of Main Cultivation Factors on Rapeseed Oil Yield

[Objective] This study aimed to analyze the influence of six cultivation fac- tors： sowing date, plant density, nitrogen fertilizer amount, phosphate fertilizer amount, potash fertilizer amount and boron fertilizer amount on seed oil yield of Brassica napus. [Method] Statistical analysis was carried out based on the data from previous studies and our work. [Result] Oil yield shared a negative correlation with sowing date, a parabolic relationship with plant density mostly, parabolic rela- tionships with amount of applied nitrogen fertilizer and amount of applied boron fer- tilizer, straight-line relationships with amount of applied phosphate fertilizer and amount of applied potash fertilizer. The average amount of applied nitrogen fertilizer required to obtain the highest oil yield was 185.18 kg/hm2 for high-oil rape varieties （with oil content above 44.00%）, and under this condition, the average oil yield of low-oil rape varieties （with oil content below 42.00%） was 1 247.84 kg/hm2, while that of high-oil rape varieties was 1 442.60 kg/hm2, which was 15.61% more than the former. The average amount of applied nitrogen fertilizer required to obtain the highest oil yield for lower-oil rape varieties was 286.28 kg/hm2, and under this con- dition, the average oil yield of the low-oil rape varieties was 1 350.57 kg/hm2, while that of the high-oil varieties was 6.81% higher than it. There was a significant neg- ative correlation between rapeseed oil yield and the amount of applied nitrogen fer- tilizer to obtain the highest oil yield （0.980 0）. The optimum amount of applied ni- trogen, phosphate, potash and boron fertilizer were 187.5-195, 187.5-195, 105-120, 135-150 and 15-22.5 kg/hm2 for high-oil B. napus varieties. [Conclusion] This study determined the influence of sowing date, plant density and amount of applied nitro- gen fertilizer on oil yield of B. napus, and proposed an optimum cultivation pattern for high-oil varieties.

Comparions of Required Nitrogen Fertilizers by Hybrid Cultivar and Conventional Cultivar of Rapeseed(Brassica napus L.)

[Objective] The aim of this study was to understand the difference of N fertilizer requirement between hybrid rapeseed and conventional rapeseed. [Method] Two hybrid cultivars, ZY5628 and ZY7819, and the conventional cultivar ZS10, were compared through two field experiments. In Experiment 1, seed yield and optimum N application rate were assessed in the field with five N application treatments. In Expedment 2, N was applied uniformly at 180 kg/hm2, and plant biomass and N accumulation were measured at several developmental stages, while N use efficien- cy was calculated for rape at maturity. [Results] The experiment 1 results showed that seed yields of ZY5628 and ZY7819 were both significantly higher than that of ZS10, and compared to ZS10, optimum yield （plateau yield） was higher by 18.7% and 20.2%, while the recommended N application rate was lower by 9.5% and 9.6% for ZY5628 and ZY7819, respectively. The experiment 2 results showed that during vegetative development, all three cultivars exhibited similar accumulations of plant biomass and N, but through flowering and maturity ZY5628 and ZY7819 pro- duced more biomass, acquired more N, and utilized acquired N more efficiently to- wards seed production than ZS10. [Conclusion] With equivalent inputs, the hybrid rapeseed cultivars ZY5628 and ZY7819 tested herein yield more seed with higher N use efficiency than the conventional rapeseed ZS10. This information will be valu- able for growers seeking to improve efficiency while reducing costs of rape production in China.

Effects of Nitrogen Fertilizer on Yield, Nitrogen Absorption and Utilization on Four Summer Maize Species

[Objective] The aim was to explore scientific application of N fertilizer for summer maize species.[Method] A test was designed to research effects of N quantities on Zhengdan No.958,Xundan No.20,Nonghua No.101 and Xianyu No.335 in terms of yield,economic benefits,accumulated nitrogen and use efficiency of N fertilizer.[Result] The increase of N fertilizer improved yields of summer maize dramatically.Specifically,with low N quantity,yield and net revenue of Zhengdan No.958 reached 18.19% and 3 158 yuan/hm^2,respectively,and yields and net revenues of Jundan No.20,Nonghua No.101 and Xianyu No.335 were 17.31% and 2 642 yuan/hm^2,25.03% and 3 726 yuan/hm^2,17.41% and 3 182 yuan/hm^2,accordingly.With N quantity increased,agricultural efficiency of Zhengdan No.958 reduced significantly and the agricultural efficiencies showed little differences among Xundan No.20,Nonghua No.101 and Xianyu No.335.[Conclusion] In practice,Zhengdan No.958 is suitable to be applied with N at low quantity,and Xundan No.20,Nonghua No.101 and Xianyu No.335 are suitable to be applied with N at high quantity.