Estimation of Land Production and Its Response to Cultivated Land Conversion in North China Plain

Food safety and its related influencing factors in China are the hot research topics currently,and cultivated land conversion is one of the significant factors influencing food safety in China.Taking the North China Plain as the study area,this paper examines the changes of cultivated land area using satellite images,estimates land productivity from 1985 to 2005 using the model of Estimation System for Land Productivity(ESLP),and analyzes the impact of cultivated land conversion on the land production.Compared with the grain yield data from statistical yearbooks,the results indicate that ESLP model is an effective tool for estimating land productivity.Land productivity in the North China Plain showed a slight decreasing trend from 1985 to 2005,spatially,increased from the north to the south gradu-ally,and the net changes varied in different areas.Cultivated land area recorded a marginal decrease of 8.0 × 105 ha,mainly converted to other land uses.Cultivated land conversion had more significant negative impacts on land produc-tion than land productivity did.Land production decreased by about 6.48 × 106 t caused by cultivated land conversion between 1985 and 2005,accounting for 91.9% of the total land production reduction.Although the land productivity increased in Anhui and Jiangsu provinces,it can not offset the overall adverse effects caused by cultivated land con-version.Therefore,there are significant meanings to control the cultivated land conversion and improve the land pro-ductivity for ensuring the land production in the North China Plain.

Developing sustainable summer maize production for smallholder farmers in the North China Plain: An agronomic diagnosis method

With an increasing population and changing diet structure, summer maize is increasingly becoming an important energy crop in China. However, traditional farmer practices for maize production are inefficient and unsustainable. To ensure food security and sustainable development of summer maize production in China, an improved, more sustainable farmer management system is needed. Establishing this system requires a comprehensive understanding of the limitations of current farming practice and the ways it could be improved. In our study, 235 plots from three villages in the North China Plain(NCP) were monitored. Maize production on farms was evaluated;our results showed that the maize yield and nitrogen partial factor productivity(PFPN) were variable on smallholder farms at 6.6–13.7 t ha^–1 and 15.4–88.7 kg kg^–1, respectively.Traditional farming practices also have a large environmental impact(nitrogen surplus:–64.2–323.78 kg ha^–1). Key yield components were identified by agronomic diagnosis. Grain yield depend heavily on grain numbers per hectare rather than on the 1 000-grain weight. A set of improved management practices(IP) for maize production was designed by employing a boundary line(BL) approach and tested on farms. Results showed that the IP could increase yield by 18.4% and PFPN by 31.1%, compared with traditional farmer practices(FP), and reduce the nitrogen(N) surplus by 57.9 kg ha^–1. However,in terms of IP effect, there was a large heterogeneity among different smallholder farmers’ fields, meaning that, precise technologies were needed in different sites especially for N fertilizer management. Our results are valuable for policymakers and smallholder farmers for meeting the objectives of green development in agricultural production.

Evapotranspiration Estimation Based on MODIS Products and Surface Energy Balance Algorithms for Land(SEBAL) Model in Sanjiang Plain,Northeast China

In this study,the Surface Energy Balance Algorithms for Land(SEBAL) model and Moderate Resolution Imaging Spectroradiometer(MODIS) products from Terra satellite were combined with meteorological data to estimate evapotranspiration(ET) over the Sanjiang Plain,Northeast China.Land cover/land use was classified by using a recursive partitioning and regression tree with MODIS Normalized Difference Vegetation Index(NDVI) time series data,which were reconstructed based on the Savitzky-Golay filtering approach.The MODIS product Quality Assessment Science Data Sets(QA-SDS) was analyzed and all scenes with valid data covering more than 75% of the Sanjiang Plain were selected for the SEBAL modeling.This provided 12 overpasses during 184-day growing season from May 1st to October 31st,2006.Daily ET estimated by the SEBAL model was misestimaed at the range of-11.29% to 27.57% compared with that measured by Eddy Covariance system(10.52% on average).The validation results show that seasonal ET from the SEBAL model is comparable to that from ground observation within 8.86% of deviation.Our results reveal that the time series daily ET of different land cover/use increases from vegetation on-going until June or July and then decreases as vegetation senesced.Seasonal ET is lower in dry farmland(average(Ave):491 mm) and paddy field(Ave:522 mm) and increases in wetlands to more than 586 mm.As expected,higher seasonal ET values are observed for the Xingkai Lake in the southeastern part of the Sanjiang Plain(Ave:823 mm),broadleaf forest(Ave:666 mm) and mixed wood(Ave:622 mm) in the southern/western Sanjiang Plain.The ET estimation with SEBAL using MODIS products can provide decision support for operational water management issues.

A Study on the Driving Factors of Food Production in Huang-Huai-Hai Plain Based on Path Analysis

The effects of 14 factors on food production in Huang-Huai-Hai Plain are analyzed by path analysis in this paper,and then the linear regression models of them are established by SPSS software. The results show that electricity consumption for agriculture,growing area of crops,the affected area,annual average temperature and arable land area at the end of the year have great effects on food production. Finally some recommendations are put forward to improve the food production in Huang-Huai-Hai Plain such as improving the level of agricultural mechanization,stabilizing food production,preventing natural disasters and increasing the effective irrigation area.

Effect of water fluctuation on agricultural production in the Huang-Huai-Hai Plain, China

The biggest load of water resources for agricultural economy in the Huang-Huai Plainwill only arcount for 67.1 % of the forecasted irrigated area in 2010. The irrigated area and thequantity of water diverting from the Huanghe River was 2.2 million hm2 and 10.8 billion m3respectively in the lowe reaches of the river in the 1990s. The annual amount of yield increase forgrain is 6.3 billion kg calculated by converting and the annual benefit of yield-increase is 4.4 billionRMB yuan in the irrigated area of the region. The daily economic losses of industry and agricultureby absence of flow in the area in the 1990s is 44. 1 million RMB yuan. The annual water quantity willbe increased by 9.9 billion m3 after diverting water from the Huanghe River and 12.6 billion m3 afterdiverting water from the Changjiang River respectively in the plain in 2010.

Evaluation on the Influencing Factors of Agricultural Land Productivity in Huang-Huai Plain,China

Taking Huang-Huai Plain as an example,evaluation index system is established from four aspects,including the resources condition,the social and economic condition,the agricultural science and technology condition,and the disaster resistant and sustainable production condition.Correlation coefficient method and expert consultation method are used to determine the weight of evaluation index.After the standardization of extreme value,weighted sum method and multiple regression method are adopted to evaluate the influencing factors of agricultural land productivity in Huang-Huai Plain,China.Evaluation result shows that agricultural science and technology condition has a lower contribution rate to the productivity of Huang-Huai Plain than that to Henan Province.Resources condition has a higher contribution rate to the productivity of Huang-Huai Plain than that to Henan Province.Both the social and economic condition and the disaster control and sustainable production condition show relatively small contribution rate to the productivity of Huang-Huai Plain.It can be concluded that the main factors affecting the productivity of Huang-Huai Plain are the backward agricultural science and technology level,the poor farmland quality and the farmland infrastructure.Based on this,relevant suggestions are put forward to improve the farmland productivity of Huang-Huai Plain.

Assessing climate effects on wheat yield heterogeneity in the North China Plain and evolution from 1960 to 2020

This study quantified climate effects on wheat yield heterogeneity in the North China Plain from 1960 to 2020,by integrating the Agricultural Production Systems sIMulator,Optimal Parameters–based Geographical Detector model,and Ensemble Empirical Mode Decomposition model.The factors dominating yield heterogeneity varied by growth stage.For sowing to anthesis,anthesis to maturation,and the entire growth season,minimum temperature,radiation,and vapor pressure deficit has the greatest effect on yield heterogeneity.Interannual periodic oscillations govern the long–term evolution of climate effects on yield heterogeneity from 1960 to 2020.

Soil Quality Evaluation and Technology Research on Improving Land Capability——A Case Study on Huanghuaihai Plain in Shandong Province

Based on the geochemical data obtained from the national project about the prevention and control of soil contamination, this paper explored the properties of soil chemical elements in Huanghuaihai Plain, Shandong Province. The results showed that among the grade-one nutritive elements in soil, organic matter, nitrogen and phosphorus were relatively deficient while potassium was rich. Meanwhile, as the grade-two nutritive elements, calcium oxide and magnesium oxide were relatively short and sulfur’s content was abundant. About the other beneficial and trace nutri-tive elements, iron oxide, manganese, molybdenum and boron were deficient, but the content of chlorine was high, hardly lack. The main barriers to improving land productivity were soil salinization and soil heavy metal contamination. The values of soil integrated fertility index that most of the soil in the study area is middle-lower fertilized. Specifical y, the low fertility area and lower fertility area are 6 1604 and 1 244 km2 respectively, occupying about 97.43% and 1.97% of the total area. The moderate fertility soil has an area of 172 km2, occupying about 0.27% of the total area. The higher fertility soil covers an area of 128 km2, while the high fertility area of only 76 km2. This article proposed scientific fertilization, elimination of soil obsta-cle, remediation of heavy-metal-contaminated soil and other effective measures to improve land productivity according to the basic investigation results, which provides a good technological support for the planning and development of good-quality and high-benefit agriculture.

Experiences and Research Perspectives on Sustainable Development of Rice-Wheat Cropping Systems in the Chengdu Plain, China

The rice and wheat cropping pattern is one of the main cropping systems in the world. A large number of research results showed that successive cropping of rice and wheat resulted in a series of problems such as hindering nutrition absorption, gradual degeneration of soil fertility, decline of soil organic matter, and increased incidence of diseases and pests. In China, especially in the Chengdu plain where rice-wheat cropping system is practiced, productivity and soil fertility was enhanced and sustained. This paper reviews the relevant data and experiences on rice-wheat cropping in the Chengdu Plain from 1977 to 2006. The principal sustainable strategies used for rice-wheat cropping systems in Chengdu Plain included： 1） creating a favorable environment and viable rotations; 2） balanced fertilization for maintenance of sustainable soil productivity; 3） improvement of crop management for higher efficiency; and 4） use the newest cultivars and cultivation techniques to upgrade the production level. Future research is also discussed in the paper as： 1） the constant topic： a highly productive and efficient rice-wheat cropping system for sustainable growth; 2） the future trend： simplified cultivation techniques for the rice-wheat cropping system; 3） the foundation： basic research for continuous innovation needed for intensive cropping. It is concluded that in the rice-wheat cropping system, a scientific and reasonable tillage/cultivation method can not only avoid the degradation of soil productivity, but also maintain sustainable growth in the long run.

Intra-specific variations of two Leymus chinensis divergence populations in Songnen Plain, Northeast China

Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.

供需评价异化视角下农业生产托管服务价格形成机制存在的问题——来自江汉平原的调查问卷

农业生产托管服务价格是影响托管服务供给和需求的重要因素。基于江汉平原农业生产托管服务供需双方对托管服务价格评价的调查结果,分析了农业生产托管服务价格形成机制的现状与存在的问题。结果表明,目前农业生产托管服务价格并不是供需双方一致达成的均衡价格,农业生产托管服务市场属于不完全市场,托管服务价格水平普遍偏高,供给方有让利给需求方的空间和动机,但存在供需错配问题,托管服务价格及补贴政策对供需的调节作用并没有得到充分发挥。为此,应完善供需沟通渠道,加强服务标准建设,大力发展新型农业经营方式,优化托管补贴对象,加强政策宣传和明确补贴指向,以促进农业生产托管服务价格形成机制的完善。

散射辐射对鄱阳湖平原典型稻田总初级生产力的影响

探明散射辐射变化对稻田生态系统总初级生产力(Gross primary productivity,GPP)的影响可为稻田碳汇能力评估和产量估算提供参考。本研究以鄱阳湖平原双季稻田为研究对象,利用涡度相关(Eddy covariance,EC)系统对稻田CO_(2)通量进行了连续两年(2017—2018年)的定位观测,选取水稻生育中期数据,按照散射辐射比例(Diffuse fraction,DF)进行分段,分析了散射辐射对稻田GPP的影响,探明并量化了不同DF条件下散射辐射与其他气象因素对稻田GPP的影响机制。结果表明:不同类型辐射对GPP的影响存在差异,GPP随着直接光合有效辐射(Direct photosynthetically active radiation,PAR_(dir))的增加先迅速增长,随后达到饱和;在不同DF条件下,早晚稻GPP随着散射光合有效辐射(Diffuse photosynthetically active radiation,PAR_(dif))的变化趋势存在差异,当DF为0.1~0.4时,早稻GPP随PAR_(dif)无明显变化趋势,晚稻GPP随PARdif呈上升趋势(决定系数R^(2)为0.23),当DF为0.4~0.7时,早晚稻GPP随PAR_(dif)呈下降趋势(R^(2)为0.38、0.02),当DF为0.7~1.0时,早晚稻GPP随PAR_(dif)呈明显上升趋势(R2为0.32、0.89),可见PAR_(dif)是影响水稻GPP的重要因素。早晚稻GPP与DF呈二次曲线关系(R^(2)为0.45、0.67),早晚稻光能利用效率(Light use efficiency,LUE)则与DF呈显著的线性正相关关系(R^(2)为0.68、0.82),早晚稻最优DF为0.48和0.40。DF变化同时引起气温(Air temperature,T_(a))和饱和水汽压差(Water vapor pressure deficit,VPD)的变化,进而对水稻GPP产生协同影响。气象因素与水稻GPP的通径分析结果表明:不同DF条件下,气象因素对水稻GPP的影响存在明显差异。总体而言,T_(a)和VPD升高分别对水稻GPP起促进和抑制作用,当DF为0.1~0.4、0.4~0.7和0.7~1.0时,影响早稻GPP的主要气象因素为T_(a)、PAR_(dir)和PAR_(dif),影响晚稻GPP的主要气象因素则为PAR_(dif)、PAR_(dir)和PAR_(dif)。

施氮对松嫩平原栽培羊草地生产性能和土壤养分的影响

为明确施氮对栽培草地生产性能及土壤养分的影响,本研究以栽培羊草(Leymus chinensis)地为研究对象,采用随机区组设计,设置不同施氮处理[N0(0 kg·hm^(-2))、N1 (42 kg·hm^(-2))、N2(84 kg·hm^(-2))、N3(126 kg·hm^(-2))],通过连续两年(2018年、2019年)试验观测,分析不同施氮水平下栽培羊草地的株高、干物质产量及土壤p H、有机质、全氮、碱解氮、全磷和速效磷变化特征。结果表明,施氮后羊草的株高和干物质产量随施氮量的增加呈先增加后减小的变化趋势,在施氮量为84 kg·hm^(-2)(N2处理)时表现最好,随后呈下降趋势。2018年和2019年,在N2处理下羊草的干物质产量较N0分别提高了43.20%(P <0.05)和22.15%。与N0相比,N2处理显著提高了2019年0-10 cm土壤全氮和全磷含量,但对p H影响不显著。相关分析表明,羊草的株高、干物质产量与土壤全磷、速效磷和有机质含量呈显著正相关关系(P <0.05),与土壤p H呈极显著负相关关系(P <0.01)。综合分析,当氮肥施用量为84 kg·hm^(-2)时,对松嫩平原栽培羊草地的羊草生产和土壤肥力改善效果最好。

刈割期对土默川平原苜蓿生产性能及经济效益的影响

试验旨在探究土默川平原苜蓿的最佳刈割时期,为苜蓿规模化生产应用提供参考。试验设置现蕾期、初花期和盛花期3个处理,每个处理3次重复。测定了土默川平原紫花苜蓿(WL319HQ)不同刈割时期的产量、营养品质和经济效益指标。结果表明:苜蓿在现蕾期刈割,全年可收获干草13011.60 kg/hm2,其粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量分别为20.69%DM、36.91%DM、26.64%DM,相对饲喂价值(RFV)为172.11,收益为16131.34~20034.83元/hm2。在初花期刈割,全年可收获干草12829.81 kg/hm2,其CP、NDF、ADF含量分别为18.55%DM、41.03%DM、30.70%DM,RFV为147.78,收益为11791.53~15640.47元/hm2。在盛花期刈割,全年可收获干草14444.64 kg/hm2,其CP、NDF、ADF含量分别为16.80%DM、45.82%DM、35.57%DM、RFV为124.40,收益低于9889.27元/hm2。研究表明,土默川平原苜蓿在现蕾期刈割的营养价值和经济效益更高。

农业生产不同环节农户托管意愿的影响因素——以江汉平原水稻生产为例

基于江汉平原水稻生产的农户调查数据,从农业生产不同环节农户托管意愿视角,分析影响农户农业生产托管水平的因素。结果表明,农户劳动力的减少以及农业生产整地环节、收割环节的高强度劳动,使得农户的生产托管意愿得到增强。在农业生产托管的技术密集型环节,专业服务组织为农户提供的农机设备及生产技术提升了农户的托管意愿,但在育秧移栽环节,设备因素对农户托管意愿具有负向影响,可能是因为育秧移栽环节的劳动强度低于其他环节,农户选择人工种植,并且农户更加信赖自身多年来积累的育秧移栽技术。农户生产经营理念的转变,追求高效便捷农业生产的求便心理,促使农户参与农业生产托管。因此,应加强粮食主产区农业基础设施建设和生产托管经营管理人才培养力度,加大政府扶持力度,建立健全农业生产性服务标准体系。

中原城市群“三生”用地动态模拟及其生态系统服务价值响应

明晰城镇快速扩张背景下“三生”用地演变过程及其生态系统响应机制,将对国土空间优化和生态安全产生重要影响。选取中原城市群核心发展区为实证对象,在2000—2020年三期土地利用解译数据基础上,运用斑块生成土地利用(PLUS)模型模拟2030年“三生”用地格局,评估中原城市群生态系统服务价值,并运用空间自相关方法探究各县区生态服务价值变化的时空演变机制。结果表明:1)2000—2030年,“三生”用地类型以农业生产用地、林地生态用地和乡村生活用地为主。2)生态系统服务总价值整体呈递增趋势,共增加36.7亿元。空间分布上,呈西北高、东南低的特征。调节服务始终是中原城市群“三生”用地生态系统的主要功能。3)所辖县区地均生态系统服务价值高值大多集聚在西部山区,低值主要集聚在许昌—漯河沿线3县区。地均生态系统服务价值增加的县区分布在黄河沿线,减少的县区多位于西南山区和亳州一带。研究结果可为面向生态保护高质量发展的中原城市群国土空间规划提供科学依据。

《温病条辨》存津液思想在宁夏平原燥证治疗中的应用

目的探究《温病条辨》中存津液、护阴思想在宁夏地区四季常见温热性平原燥证中的临床应用。方法对《温病条辨》存津液思想归纳总结,将三焦辨证作为治疗宁夏平原燥证的总纲。结果上焦以辛凉之品祛燥邪外为主,配伍甘寒之品生津润肺为辅;中焦以甘(凉)寒为主,益胃生津;下焦以甘凉、咸寒之品填补真阴,存津液潜阳。同时忌辛温、慎苦寒、禁渗利,重存肺胃之阴、保津重于养阴,达到未病先防、既病防变之功。结论《温病条辨》存津液思想对宁夏平原燥证治疗具有一定的临床指导意义。

土壤-农产品重金属累计特征及健康风险评价——以三江平原东部某典型农业区为例

为掌握三江平原东部某典型农业区农田土壤和农产品重金属累计特征及评价其健康风险,本文以三江平原东部面积约180 km^(2)的某典型水稻种植区为研究对象,采用梅花法进行布点取样,共采集土壤样品和农产品样品各50件,采用电感耦合等离子体质谱仪、原子荧光分光光度对土壤和农产品中Cr、Ni、Cu、Zn、Cd、Pb、As、Hg重金属含量进行测定,采用污染负荷指数法分析土壤重金属污染水平,运用重金属健康风险评估模型评估农产品中重金属的非致癌和致癌风险。结果表明,研究区土壤重金属近半数点位处于中等污染水平,水稻中Ni和As超标可能造成食品安全风险。研究区水稻样品中As是非致癌风险的主要污染物,通过摄入研究区水稻暴露于重金属As会对人类健康造成非致癌风险;Ni、Pb、As和Cr是致癌风险的主要污染物,通过摄入研究区水稻暴露于Ni、Pb、As和Cr将会对人类造成致癌风险。研究结果可为粮食作物安全和环境管理提供决策依据。

中原文化赋能“豫农”品牌的价值审视

农产品区域品牌建设是促进区域农业产业化发展、带动乡村振兴的重要推手。创建农产品区域品牌,不能局限于从时下流行的“健康”“绿色”“安全”等产品物理属性的价值点开展,也应从“地域文化”找到其特殊的精神属性。文化是品牌的核心与灵魂。在“品牌强省”建设过程中,河南应善于从中原文化中汲取养分和力量,将“中原文化”与“出彩河南”联系起来。挖掘文化资源“富矿”,赋能“豫农”品牌,不仅能构建差异化竞争优势、提升产品附加值,还能助推中原文化传播、提升从业人员的自豪感与自信心。

河南省建筑用钢筋产品质量情况分析及建议

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