河南省小麦-玉米轮作系统光能利用率时空分布及其变化原因分析

利用河南省19个农业气象试验站的气象和小麦、玉米观测资料,计算1981-2007年作物生长季辐射和年总辐射量、小麦、玉米生长季和轮作系统的作物产能及光能利用率（Radiation Use Efficiency,RUE）,分析总辐射和作物产能变化对RUE变化的贡献、小麦和玉米产能变化分别对轮作系统产能变化的贡献。结果表明,河南省小麦-玉米轮作系统RUE为0.75%~1.61%,北部的汤阴和西部的卢氏是高值区,西北、东部偏东和南部地区较低。小麦生长季RUE为0.65%~1.63%,北部的汤阴和西部的卢氏最高,东部偏中大部分地区次之,而西北和东部部分地区最低,玉米生长季RUE为0.85%~1.81%,除西部的三门峡RUE在全区最低外,北部和西部大部分地区较高,而西北和东部、南部地区较低。1981-2007年,卢氏、汝州、西平、新乡和驻马店5个站点小麦-玉米轮作系统RUE呈显著升高趋势（P〈0.05）。在轮作系统RUE变化显著的站点中,除卢氏站点因年总辐射升高对RUE变化呈负贡献外,其余站点的贡献率为4%~31%,系统作物产能变化对RUE变化的贡献率为69%~96%。卢氏和汝州站点小麦产能变化对系统作物产能变化的贡献率（65%和90%）大于玉米（35%和10%）,而西平、新乡和驻马店站点小麦产能变化对系统作物产能变化的贡献率（49%、28%和35%）小于玉米（51%、72%和65%）。未来提高单位面积的作物产能仍是提高区域RUE的有效方法,且不同地区应着重提高不同作物的产能。

A study on the bioenergy crop production function of land use in China

Based on the analysis of the bioenergy crop production function of land use,combined with the status quo of Chinese land use,the cultivation of energy plants and the bioenergy crop production function of land use had been analyzes and discusses in this paper.Results show that there were a lot of unused lands and marginal lands which can be planted bioenergy crops to perform the bioenergy crop production function of land use with great potentials;and currently there were no food production problems.Therefore,it was very important for China to emphasize bioenergy crops planting in order to fully use land resources in our country,moderate the energy crisis and increase peasants' income.

Effect of Tillage and Planting Methods on the Soil Properties, Grain Drill Performance, and Wheat Yield

The effect of conservation tillage methods and seeding machines on the soil physical properties, performance of grain drill, wheat yield, and wheat yield components was evaluated. The research was conducted in a split block experimental design with twelve treatments and four replications, and a local wheat variety （Shiraz） was planted in this study. Main plots were tillage methods including： （1） primary tillage using moldboard plow without moldboard; （2） primary tillage with disk harrow; and （3） primary tillage with chisel plow. Subplots were grain drill types including： （1） planting with Taka grain drill without furrower; （2） planting with Taka grain drill having furrower; （3） planting with Hamadan Machine Barzegar grain drill having furrower and runner opener; 4） planting with grain drill having ripple opener. Parameters including mean weight diameter of clods （MWD）, soil bulk density, uniformity of seed planting depth, seed distribution uniformity, seed emergence, crop yield, and crop yield components were measured. SAS software was used to analyze the collected data and the method of benefit to cost ratio was used to compare the treatments from the economic point of view. Results indicated that tillage method had no significant effect （P = 0.05） on the measured parameters. Plant per unit area, seed emergence, uniformity of seed planting depth, and MWD were significantly affected by the grain drill type （P 〈 0.05） while, the type of grain drill had no significant effect on the rest of measured parameters. Taka grain drill without furrower had the highest uniformity of planting depth and proper soil MWD, and grain drill with ripple opener had the highest seed emergence and plant per unit area. Interaction between tillage methods and grain drill types affected the soil MWD, seed emergence, and crop yield （P 〈 0.05） in such a way that the combination of primary tillage with disk harrow and planting with grain drill having ripple opener provided the highest crop yield.

Energy Balance in Crop Production

The most appropriate method of energy balancing in crop production is the process analysis where fossil energy input is considered rather than manpower or solar energy. In our approach, fossil energy input is split to direct and indirect input components. Direct energy input includes the consumption of diesel fuel required for field operations taking into account the influences of location and management conditions. Moreover, energy consumption for construction of agricultural machines is also considered as direct energy input. Indirect energy inputs include seed material, plant protection agents, fertilizers and operation of machines. Production and utilisation of nitrogen （N） fertilizer represents by 50% of energy consumption in agricultural systems. Data from a field experiment conducted during 1995-2000 on a fertile sandy loess in the Hercynian dry region of central Germany were used to determine the energy efficiency of winter oilseed rape （Brassica napus L.） as affected by nitrogen （N） fertilization. Our results show that different N management strategies affect the energy balance of the seed oil. Lowest energy input and energy output occurred in the unfertilized crop. The energy efficiency was determined using the parameters energy gain （net energy output）, energy intensity （energy input per unit grain equivalent GE; term GE is used to express the contribution that crops make to the nutrition of monogastric beings）, and output/input ratio. The most favourable N rate for minimum energy intensity was 80 kg N hal while that needed for maximum energy gain was 160 kg ha1. Output/input ratio was the highest at 80 kg N ha-l.

Evaluation of Potential Productivity of Woody Energy Crops on Marginal Land in China

Energy crops are a basic material in the bioenergy industry, and they can also mitigate carbon emissions and have environ- mental benefits when planted on marginal lands. The aim of this study was to evaluate the potential productivity of energy crops on marginal lands in China. A mechanistic model, combined with energy crop and land use characteristics, and meteorological and soil parameters, was used to simulate the potential productivity of energy crops. There were three main results. 1） The total marginal land in China was determined to be 104.78 × 106 ha. The 400-mm precipitation boundary line, which is the dividing line between the semi-humid and semi-arid zones in China, also divided the marginal land into shrub land and sparse forest land in the southeast and bare land, bare rock land, and saline alkali land in the northeast. 2） The total area of the marginal land suitable for planting energy crops was determined to be 55.82 × 106 ha, with Xanthoceras sorbifolia and Cerasus humilis mainly grown in the northern China, Jatropha curcas and Comus wilsoniana mainly grown in the southwest and southeast, and Pistacia chinensis mainly grown in the central area, while also having a northeast-southwest zonal distribution. 3） Taking the highest yield in overlapping areas, the potential productivity of target energy crops was determined to be 32.63 × 106 t/yr. Without considering the overlapping areas, the potential productivity was 6.81× 106 t/yr from X. sorbifolia, 8.86× 106t/yr from C. humilis, 7.18 ×106t/yr from J. curcas, 9.55 × 106t/yr from P. chinensis, and 7.78 ×106 t/yr from C. wilsoniana.

The Production of Biofuels in South Africa： Policy and Availability of Energy Crops

Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy sources; and by dealing with environmental issues. One such environmental issue is the unsustainable use of agricultural land. There is a need in South Africa there to convert to sustainable and renewable energy resources, such as biofuels, but the production of biofuels will ultimately place pressure on the limited and fragile agricultural resources of the country. This paper sets out firstly to investigate national agricultural policies which could impact on the production of biofuels. It points out that national agricultural policies are hampering the domestic production of biofuels in that the focus is on land reform and increasing the volume of agricultural exports, whereas the provision of food and energy to meet domestic needs features only as a secondary aim. The second objective of this paper is to investigate the possibility of utilising energy crops for biofuel production in South Africa. Annual agricultural production, surplus import and export figures, provide an indication of the capacity of South African farmers to produce crops for biofuel production.

基于APSIM模型的北方农牧交错带轮作种植模式设计——以河北省张北县为例

多样化轮作是缓解北方农牧交错带作物种植结构单一、土壤退化、生态功能弱化等问题的重要途径,定向设计区域适宜性的轮作模式对协调农业生产和生态保护等多目标协同至关重要。文中基于河北省张北县2017-2021年的轮作制度长期定位试验数据,利用作物模型APSIM(Agricultural Production Systems Simulator)进行调参与验证,评价了该模型在该区域的适用性,并利用验证后的APSIM模型模拟了该地区4种特色作物228种轮作模式10年的生长过程,基于投入产出和碳足迹评价法定量分析不同轮作模式的产能、生态效益与经济效益。结果表明,APSIM模型对研究区燕麦(Avena sativa L.)、马铃薯(Solanum tuberosum L.)、蚕豆(Vicia faba L.)和胡麻(Sesamum indicum L.)生产模拟的精度较高,归一化均方根误差(NRMSE)为4.3%-15.4%。在228种轮作模式模拟中:从能量当量产量来看,燕麦-蚕豆轮作模式的10年总能量当量产量最高,为4.13E+05 GJ/hm^(2)。从生态效益来看,马铃薯-蚕豆轮作模式的10年总净碳排放量最低,为0.42 t·C/hm^(2)。从经济效益来看,胡麻-蚕豆轮作模式的10年总综合收益最高,为65857.09元/hm^(2)。研究结果基于作物产能-生态效益-经济效益等多目标需求,为不同主体的不同需求对应选择适宜的轮作模式提供了理论依据。

部委声音

水资源是战略资源必须强化管理最近召开的全国水利厅局长会议上,回良玉副总理做了重要批示。他说,水资源是战略资源,水利是经济和社会发展的命脉。要树立全面、协调、可持续的发展观,进一步做好防讯抗旱工作,加强水利基础设施建设,强化水资源统一管理,完善水利发展机制和体制,为全面建设小康社会提供有力的支撑和保障。

阴山北麓旱作区主要作物热能值及结构调整研究

阴山北麓农牧交错地带,气候干旱冷凉,种植结构单一,生产能力低而不稳。农业生产不仅要考虑作物综合生产能力,同时要考虑其水分消耗数量。作物的热能产值反映了其综合生产能力。文中采用能值研究方法,通过田间试验、实验室分析测试对该地区三年主要作物的热能产值、耗水量及其生物产量和经济效益进行了系统研究,结果表明,当地主要作物的热能值大小依次为:向日葵>玉米>马铃薯>草玉米>草谷子>草莜麦>油菜>莜麦>小麦>胡麻>箭筈碗豆>山黧豆。考虑到热能值、生物产量、经济效益和水分生产能力,该地区种植结构调整首先应考虑马铃薯的种植,其次是向日葵,然后是饲草和杂粮。优化作物布局,可以获得作物综合生产能力和环境资源保护的双赢,能够促进资源合理利用与农牧业的可持续发展。