如何使大豆中产变高产

中产变高产就是由６６７米２产１５０公斤变成６６７米２产２５０公斤的水平。要高产需以下措施:一、增施农家肥。一般６６７米２施优质农家肥２０００－３０００公斤或饼肥４０－５０公斤。若夏种时忙,可把准备施在前茬小麦上的有机肥一块施入,使大豆用残肥。此外,６６７米２施二铵３０公斤,氯化钾７．５公斤。二、选用良种。选高产潜力大、抗倒伏。

Effects of the Application of Controlled Release Nitrogen Fertilizer on Rapeseed Yield, Agronomic Characters and Soil Fertility

In order to study the effects of controlled release nitrogen fertilizer （CRNF） application on rapeseed, a simulated experiment was carried out with 3 types of paddy soils in Dongting Lake area for 4 consecutive years of applying CRNF under double rice cropping system after planting rapeseed crop in the fallow season. The effects of CRNF application on rapeseed yield, agronomic characters and soil fertility were studied in this paper. The results showed that CRNF application improved the growth of rapeseed plant and increased rapeseed yield of CRNF treatments in the purple calcareous clayed paddy soil （PCS） and alluvial loamy paddy soil （ALS） which respectively increased by 12.2% and 9.8% compared with applying urea, re- spectively. The rapeseed yield in 70% CRNF treatment obviously decreased com- pared with urea treatment. The contents of available N and organic carbon in soil increased by 25.0% and 3.2% in CRNF treatment in the ALS after rapeseed crop, respectively; and available N increased by 13.5% in the PCS. Both rapeseed yield and soil fertility in CRNF treatment and 70% CRNF treatment were lower than those in CK treatment in the reddish yellow clayed paddy soil （RYS）. The results al- so indicated that the functions of CRNF application on rapeseed yield increase and soil nitrogen fertility improvement were very obvious in the PCS and ALS.

Influence of Long Term Fertilization with Different Mineral Fertilizers and Farmyard Manure on Some Soil Chemical Properties and Crop Yields *1

A long term fertilization experiment was carried out in an experimental field in Lyczyn near Warsaw, Poland. Application ofmineral fertilizers, especially N fertilizers with and without farmyard manure accelerated the acidification process of the soil. Application of 1.6 t CaO ha -1 every four years was essential to maintenance of the soil pH KCl at 5.5～6.6 and base saturation degree above 60%. Application of 50 t farmyard manure ha -1 every 4 years, which contained 46 kg P and 240 kg K, was sufficient to maintain both the K and P fertility of the soil. Besides, it was beneficial to alleviating soil acidification. As a result of long term unbalanced fertilization, yield responses to N, P and K fertilizers increased significantly with time. The efficiency of N from farmyard manure was found to be comparable to that of N fertilizer during 1988～1991.

The Long Term Evolution of Phosphates from the Cambic Chernozem at ARDS Caracal, Romania

The decreasing of the plant available phosphorus of Romanian soils after 1990 is a major concern in relation with the lowered yields of the major crops. This fact is correlated with a rudimentary technology where the fertilization is a secondary issue. Thus, the fertilizer consumption, after 1990, has drastically decreased to 41.3 kg/ha NPK on arable land over 129.9 kg/ha in 1986 and from 86.4 kg/ha to 26.3 kg/ha on agricultural land. As a result, the phosphorus fertilizer quantities applied by small farmers are very small or inexistent. In order to determine the soil available phosphorus content in Romania, it was analyzed the evolution of soil phosphorus supplying degree on a cambic chernozem （one of the most fertile soils in Romania） from Agricultural Research and Development Station （ARDS） Caracal between 1986-1992 and 2000-2005. This analysis has shown the following issues： very well supplied soils by available phosphorus no more exist since 2006, the ones with a good supplying degree have decreased from 616 ha to 107 ha, which means from 24.8% to 4.3% yet the low supplied soils have increased from 526 ha to 1,129 ha （23.1% to 45.5%） and the very low supplied ones have increased from 198 ha to 776 ha （7.9% to 31.2%）. As a consequence of low fertilizer quantities and the decreasing of the soil supplying degree by available phosphorus the average yield in this farm has decreased from 5,776 to 3,707 kg/ha.

Relation between Yields of Wheat Varieties Mainly Popularized in Different Eras and Soil Fertility in Shandong Province

[Objective] This study was conducted to guide wheat production, variety breeding and extension. [Method] The evolution of agronomic traits and correlation between yield and agronomic traits of wheat varieties mainly popularized in different eras were investigated under high and low soil fertility conditions. [Result] Under dif- ferent soil conditions, there was a yield increasing trend, and the yield increasing degrees of varieties popularized in different eras were different. Soil fertility had no remarkable effects on grain number per spike, spike number, and yields of varieties popularized in the 1950s and the 1960s, while the differences in other indexes all reached the significant level. The interaction between fertility and variety had a greater effect on spike number. Under different soil fertility conditions, there were positive correlation between yield components, and the correlation coefficients were in order of spike number 〉 1 000-grain weight 〉 grain number per spike. Soil fertili- ty remarkably affected spike length and spikelet number. [Conclusion] High fertility could promote the coordinated growth of yield components.

Recent Development in Maize Research at Institute for Agricultural Research, Samaru, Nigeria

Maize research at Institute for Agricultural Research, Samaru, Nigeria resulted in sustained growth in yields in the last two decades. Maize is grown throughout the country with guinea savanna as the most important maize growing zone. In the last five years, four new open pollinating varieties developed in collaboration with the International Institute of Tropical Agriculture （IITA, Ibadan） had been released for production. Hybrid varieties are also marketed by seed companies. The research was focused on variety improvement, improved management practices, integrated pests and disease control, soil fertility management, on-farm testing of improved production packages and socio-economics of production as well as adoption studies. The recently released quality protein maize has improved the nutritional status of vulnerable groups. Drought tolerant maize for Africa research project has contributed to sustainable maize production, poverty reduction and food security in the continent.

Feeding Biochar to Cows:An Innovative Solution for Improving Soil Fertility and Farm Productivity

Addition of biochar produced through thermal decomposition of biomass has been seen as a strategy to improve soils and to sequester carbon （C）, but wide scale implementation of the technology requires to devise innovative profitable solutions. To develop biochar utilisation with an integrated system approach, an innovative program was implemented in 2012 on a 53-ha farm in Western Australia to determine the costs and benefits of integrating biochar with animal husbandry and improvement of pastures. Biochar was mixed with molasses and fed directly to cows. The dung-biochar mixture was incorporated into the soft profile by dung beetles. We studied the changes in soil properties over 3 years. Biochar extracted from fresh dung and from the soil to a depth of 40 cm was characterised. A preliminary financial analysis of the costs and benefits of this integrated approach was also undertaken. The preliminary investigation results suggested that this strategy was effective in improving soil properties and increasing returns to the farmer. It was also concluded that the biochar adsorbed nutrients from the cow＇s gut and from the dung. Dung beetles could transport this nutrient-rich biochar into the soil profile. There was little evidence that the recalcitrant component of the biochar was reduced through reactions inside the gut or on/in the soil. Further research is required to quantify the long-term impact of integrating biochar and dung beetles into the rearing of cows.