Variation Character of Grain Yield per Unit Area in Main Grain-producing Area of Northeast China

Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey correlation analysis. The results show that: 1) the grain yield per unit area has been taking on an increasing trend in the recent 20 years. It increased from 2519.80kg/ha in 1980 to 4216.11kg/ha in 2003, with an increasing rate of 67.32%; 2) the variation of grain yield per unit area is considerably prominent and its range is also very great, with the maximal increase rate of 42.59% and maximal decrease rate of 21.13%, respectively, which are far above the whole Chinese average level; 3) the variation of main crops' yield per unit area is remarkable, which takes on the character that the yield of corn is much higher than that of soybean and rice; and 4) the grey correlation analysis shows that the most important factors impacting the variation of grain yield per unit area are the total power of agricultural machinery, the consumption of chemical fertilizer and effective irrigated area. However, the influence of natural disaster and income level should not be ignored. Effective ways to improve grain yield per unit area are to construct farmland improvement groundwork, reclaim the middle- and low-yield farmland, etc.

Influences of Different Distances between Ridges or Plants on Yield of Sweet Potatoes

Based on the combination test of various distances between ridges or plants, the influences of corresponding cultivation techniques on the per unit area yield of a variety of sweet potatoes Xushu 22 in Xianning City were analyzed. The results show that different distances between ridges or plants had significant effects on the per unit area yield of Xushu 22; when the distances between ridges and plants for Xushu 22 planted in the city were 80 and 21 cm respectively, the per u- nit area yield of Xushu 22 was the highest, up to 48 340.7 kg/hm2.

Effect of Climate Change on Yield of Winter Wheat in Jiangsu Province

The spike-grain structure and yield data of winter wheat observed at 10 winter wheat observation stations in Jiangsu agrometeorological observation stations in the China Meteorological Observation Network were used to design the assessment model and evaluation criteria of the effects of climate change on spikegrain structure and yield of winter wheat. The linear regression method was used to determine the parameters of the assessment model,and the climate fact extrapolation method was used to determine future climate change scenarios. The effects of climate change on spike-grain structure and yield of winter wheat in Jiangsu Province were calculated and analyzed finally. The results showed that with the climate change,the meteorological conditions during the growth and development of winter wheat changed,which caused the number of effective spikes to decrease,and the number of grains per spike and thousand-grain weight to increase,and this new type of spike-grain structure combination was beneficial to the increase of the unit yield of winter wheat. The variations of meteorological elements caused by climate change during winter wheat growth and development had different effects on spike-grain structure at different growth stages. The spike-grain structure had an "increasing-decreasing" periodic variation with the growth period overall,with a period of one to three stages. The relationship between winter wheat growth and development and meteorological conditions can be adjusted in real time through stress-resistant cultivation techniques to achieve the high-yield and high-quality cultivation target of winter wheat production.

Analysis of Yield Components of Japonica Rice Tong Jing 981 under Different Density and Fertilization Conditions

The yield and yield components of Japonica variety Tongjing 981 under different density and fertilization levels were studied through regression and correlation and path analysis. The results showed that the number of panicles per unit area, number of filled grains per panicle and 1 000-grain weight all had very significant yield increasing effects, and the number of panicles per unit area played a leading role. However, the yield increasing effects of the number of panicles per unit area and number of filled grains per panicle are equally important when the basic seedlings are more or the N fertilizer application rate is large. In practical production, a major factor should be determined among the yield components, and rational cultivation measures should be taken accordingly, to improve yield.

有土斯有粮:高标准农田建设提高了粮食单产吗?

作为“藏粮于地,藏粮于技”战略的重要政策实践,高标准农田建设被期待能够有效实现粮食增产和更好保障国家粮食安全。基于27个省(市、自治区)的面板数据,探索了高标准农田建设对粮食单产的影响及其可能机制。研究发现:(1)高标准农田建设能显著提高粮食单产。替换核心变量、进行非参数估计和考虑内生性的稳健性检验,均证实上述发现可信。(2)机制验证表明,高标准农田建设主要通过提升规模经营、促进技术进步和降低生产风险三大路径来提高粮食单产。(3)异质性分析发现,高标准农田建设对起伏度较小地形、粮食主产区、较发达地区的粮食单产促进效应更大。研究结果表明高标准农田建设确实是夯实粮食安全根基的重要举措,需扎实推进新一轮高标准农田建设工作。

藏粮于地:土地利用对粮食单产的影响

基于“藏粮于地”战略背景,采用全国10省(区、市)950户农户数据,在将土地利用分为规模经营、可持续耕作、结构调整的基础上,利用普通最小二乘法、两阶段最小二乘法和调节效应模型实证分析土地利用对农户粮食单产的影响效应与路径。结果表明:规模经营对粮食单产的影响呈先增后减趋势,即呈倒“U”形关系,可持续耕作能够显著提升粮食单产,而结构调整显著负向影响粮食单产;规模经营在可持续耕作、结构调整影响农户粮食单产中具有正向调节效应;对于耕地禀赋不同的农户,规模经营、可持续耕作对农户粮食单产的影响存在差异性。

福建漳州平和柚天气指数保险产品设计与定价

柚产业是福建省漳州市平和县的支柱产业,为分散当地柚生产的经营风险,基于福建省漳州市平和县1985−2022年柚产量及对应年份3月中旬至8月上旬的天气数据,将柚单产数据分解成趋势单产和气象单产,并调整单产数据使其转化到2024年的生产力水平下的单产,选用核密度估计法拟合该序列的概率密度函数并用于纯费率厘定;而后利用调整后单产数据和天气数据进行相关性分析,筛选显著的天气指数。结果显示:4月中下旬降雨量指数与调整后单产的线性关系最为显著。对于2024年约定的保障产量51000 kg·hm^(−2)和保险价格2.8元·kg^(−1),即每667m^(2)保险金额为9520元,厘定纯费率为4.0191%、保险费率为4.6220%;对于降雨量指数RI的保险赔付触发值160 mm以及RI的8个分级赔付区间,分别计算得到了对应的赔付事件发生概率,并给出了对应的赔付金额计算公式。

农机作业服务提高了粮食单产吗?——来自139个县农机购置补贴十年的历史证据

农业社会化服务是否能促进农业生产率,是推进中国式农业现代化需要回答的重要问题。以粮食生产中的农机作业服务为例,利用全国139个县域在实施农机购置补贴政策后十年间的面板数据,对农机作业服务水平与粮食单产之间的关系进行实证检验。结果发现,在控制了土地、劳动力、资本等投入要素之后,农机作业服务水平对粮食单产具有显著的促进作用,并且该作用在粮食主产区更为凸显;农业机械购置补贴政策使农机作业服务对粮食单产的影响出现阶段性差异,即在政策实施初期“购机”有效促进了“用机”,农机作业服务的粮食增产效应较为明显,而后期着力于“购机”的政策无法保障持续发挥农机作业服务的粮食增产作用。因此,需通过设立农机作业补贴等形式持续有效地发挥农机作业服务的粮食增产效应。

Comparative Advantage of Maize Production in Jilin Province

The comparative advantage of maize production in Jilin Province was analyzed based on the sow area index,unit yield index,benefit index and comprehensive comparative advantage index in this study.The results showed that compared with other provinces in China,there was obvious comparative advantage in sow area index and unit yield index of maize in Jilin,the average of which stood for the first and the fourth in China from 2002 to 2006;there was no comparative advantage of benefit index compared with the average value of the whole countries,the average of which stood for the 14th in China from 2002 to 2006;the comprehensive comparative advantage in Jilin provincial maize production showed significant comparative advantage,the average of which stood for the fourth in China from 2002 to 2006.On the basis of the above,the suggestions to develop maize production in Jilin province had been put forward.

集成学习结合多源数据预测河南省冬小麦单产

为探讨基于多源数据和集成学习算法预测冬小麦单产的可行性并确定冬小麦单产预测的最佳时间窗,该研究在河南省冬小麦生长季内划分28个不同的时间窗,使用8种不同的机器学习算法及基于Stacking的集成学习算法,利用2003—2018年的多种遥感指数数据、气象数据进行训练并预测2019—2021年单产。结果表明:引入日光诱导叶绿素荧光(solar-induced chlorophyll fluorescence,SIF)特征可以提升河南省冬小麦单产的预测效果;12月至次年5月为机器学习算法预测冬小麦单产的最佳时间窗;Stacking集成学习算法比其他单机器学习算法更适用于河南省县级尺度冬小麦单产预测,预测结果的决定系数为0.816,均方根误差和平均绝对误差分别为580.36和476.01 kg/hm^(2);河南省冬小麦实际单产的空间分布呈西低东高的趋势,预测的单产分布特征与实际单产分布特征相当。研究结果可为冬小麦单产预测提供一种新的方法,也为农作物单产预测模型构建提供新的思路。

广东省2000—2021年海水养殖的时空变化特征分析

以2000—2021年广东省海水养殖数据为基础,通过时序统计、行业集中度指数、区位熵指数等方法,分析了广东省22年来海水养殖产业数据的时序变化、空间差异和分布格局,揭示了广东省海水养殖时空变化特征。结果表明:2000—2021年,广东省海水养殖区域总体呈现先分散、后连片、再逐渐向西部集中的变化趋势;在海水养殖总面积阶段性下降的同时,养殖总产量波动增长,单产水平也随之增长;全省海水养殖产量排名前4位的地市由阳江、茂名、湛江和江门市(2000—2007年)转变为湛江、阳江、茂名和汕尾市(2008—2021年);2021年,阳江和茂名市是广东省海水养殖高水平单产城市,分别为35.69和32.83 t/hm^(2);湛江市是广东省海水养殖面积和养殖产量最大的地市,养殖面积占全省的33.86%,但湛江市海水养殖单产始终低于16 t/hm^(2),处于较低单产水平。在海水养殖区位熵分析中,2003—2021年间,区位熵始终大于1的地市有3个,占海水养殖全部城市的21.43%,分别是汕尾、阳江和湛江市;平均值大于1的地市有7个,占海水养殖全部城市的50.00%,分别是汕头、惠州、汕尾、阳江、湛江、茂名和潮州市。综上,2000—2021年,广东省海水养殖产业存在明显的时空分布变化特征;粤西地区部分地市仍存在单产较低的现象,因此广东省在充分利用区位优势调控海水产养殖产业分布格局的同时,应提高养殖主产区的养殖效率,进而带动全省渔业产业高质量发展,为广东省海水养殖产业结构调整和布局优化提供参考。

镇宁县油菜单产提升技术浅析

通过分析当前镇宁县油菜种植现状,揭示其在品种选择、种植技术及防灾减损等方面存在的问题,提出了针对性的提升措施,旨在提高油菜的产量和品质,推进农业现代化,加强可持续发展。

Changes and Effecting Factors of Grain Production in China

Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors. The results show that： 1） During 1980 to 2007, total grain production increased from 3.20 ~ 108 t to 5.02 x 108 t in China, with annual increasing rate of 1.68%. From the regional disparities, most of the regions present increasing trend of total grain production except for several regions with higher level of economic development; 2） Grain sown area decreased from 1.17 × 108 ha in 1980 to 1.06 x 108 ha in 2007, which has negative effect on total grain production; 3） The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly. However, as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input, the less enthusiasm of farmers in grain production may become an important constraint on fu- ture grain production increase in China; 4） Based on the results, this paper proposed different land management poli- cies in different regions, for example, the government should protect cultivated land, promote large scale production. As to the less developed regions, the government should pay more attention to agricultural subsidies to promote farm- ers＇ enthusiasm in grain production.

Analysis of Rubber Planting in Malaysia

There are state-owned and privately-owned rubber plantations in Malaysia,of which most of them are privately owned. In Malaysia,most rubber gardens are small,and the ratio of small rubber gardens to large rubber plantations is approximately 10∶ 1. In Malaysia,the plating area of rubber trees was only 4 200 ha in 1900,1. 30 million ha in 1961,and 1. 07 million ha in 2014. It was the highest in 1978,up to 1. 89 million ha. It was the lowest in 2010,only 1. 02 million ha. The per unit area yield of rubber in Malaysia was 6 074 hg/ha in 1961 and 6 274 hg/ha in 2014. The maximum 10 285 hg/ha appeared in 1987,while the minimum 5 492 hg/ha appeared in 1999. The per unit area yield of rubber in Malaysia fluctuated greatly. Rubber yield in Malaysia was 790 000 t in 1961,and it was the highest in 1988( 1. 66 million t) and the lowest in 2014( 670 000 t).

Is the Farmland of China Sufficient?——Analysis Based on the Second National Land Survey

According to the data of the second national land survey,the farmland area of China at the end of 2009 was 200 million mu more than the original statistical data.This raises widespread concern.Analysis is carried out from the perspective of task,technique,necessities and effect on China's grain security of the second national land survey.Through analysis,it can be deemed that data of the second national land survey are reliable.It overcomes defects of traditional survey projects and will be of profound significance for grasping current situations of farmland resources in China.Farmers are grain production entities,while the grain yield survey of farmers is calculated through sampling survey of per unit area yield and the sown area.Therefore,the increase in farmland area may indicate underestimation of the grain yield,and the grain security risk of China will decline accordingly.

Study on Development of Oil Palm in Malaysia

In the 1960 s,Malaysia planted oil palm on a large scale. In the 1970 s,it became the world's largest producer and exporter of palm oil. To further explore the development prospects of the oil palm industry in Malaysia,this paper first introduced the development of oil palm in Malaysia,and analyzed the world's share of Malaysian oil palm harvested area,production,yield during 1980 and 2016. The results showed that the oil palm harvested area in Malaysia reached the peak value 5. 23 million ha in 2013; the yield of oil palm fruit reached the peak value98. 34 million t in 2015; the yield of oil palm fruit fluctuated between 14-20 t/ha; the ratio of Malaysian oil palm yield to world oil palm production reached its peak 51. 99% in 1989. Therefore,Malaysia should update the old oil palm plantation. The development of oil palm harvested area and yield has reached the peak value,it is difficult to increase the harvested area. The proportion of Malaysian oil palm industry to the world oil palm industry is constantly declining. In future,the per unit area yield of Malaysian fresh oil palm fruit is expected to reach a new peak,and fresh oil palm fruit will exceed 20 t/ha.

我国大豆生产波动动因分析——基于省际面板模型的实证研究

在我国大豆生产波动频繁的情况下,找出影响大豆单产、种植面积的影响因素是实现“提单产、稳面积”的首要举措。研究采用1999~2020年21个省份面板数据,在分析大豆单产、种植面积的变化趋势基础上,根据大豆单产增减趋势,把大豆产区划分成增产区、减产区和波动区,采用改进的面板数据模型分别对三个产区的大豆单产和种植面积的影响因素进行实证分析。结果表明,机械化收割、产研结合、农药投入、小型拖拉机的投入是影响不同区域大豆单产的显著因素;机械化耕作是提升所有区域种植面积的显著因素,玉米种植面积、化肥投入、农药投入、灌溉条件、科研资金与人员投入、产研结合、机械化收割是影响不同区域大豆种植面积显著因素。根据分析,提出了相应政策建议。

基于小波分析法的气象因子对河南省夏玉米单产的影响

[目的]全球气候变暖已对农业生产产生深远的影响.传统的多元线性回归分析方法不能直接分析气象因子与夏玉米气象单产间的周期变化.[方法]根据1988-2018年河南省13个气象站点的气象数据,利用连续小波变换分析方法探讨了河南省31 a夏玉米全生育期(6月至9月按旬分段)的平均温度、降水量、日照时数、气象单产的周期变化特征;利用相干小波变换分析方法探讨了气象因子与夏玉米气象单产间的相互影响关系.[结果](1)近31 a,河南省夏玉米气象单产占实际单产的比重逐渐降低,对于气象灾害抵御能力逐步增强.(2)从周期变化来看,6月上旬的平均温度有6 a显著周期变化;8月中旬的平均温度有2~3 a显著周期变化;7月下旬的降水量有2~6 a显著周期变化;8月中旬的日照时数有2 a和3 a显著周期变化;夏玉米气象单产有2 a显著周期变化.(3)从气象因子与夏玉米气象单产间的关系来看,6月上旬种子萌发期平均温度和8月中旬灌浆期平均温度与夏玉米气象单产呈负相关关系;7月下旬抽雄期降水量与夏玉米气象单产呈正相关关系;8月中旬灌浆期日照时数与夏玉米气象单产呈正相关关系.[结论]6月上旬种子萌发期和8月中旬灌浆期平均温度的降低,7月下旬抽雄期降水量和8月中旬灌浆期日照时数的增加有助于提升夏玉米单产.

基于时序聚类的河南省冬小麦单产演变区域差异及其对气候干湿变化的响应

依托17个地级市1988-2017年单产资料,运用时序聚类方法对河南省冬小麦产量变化模式进行了空间区域划分。在气候产量提取的基础上,运用标准化降水指数(SPI)分析了不同区域冬小麦产量对气候干湿变化的响应。结果显示:基于单产时序特征的差异,通过K均值聚类将河南省划分成西部、中西部、中北部、东部4个子区域;中北部和东部地区冬小麦的稳产、增产、高产水平较高,而西部地区冬小麦的气候灾害损失风险较高;2月SPI对西部及中西部地区的冬小麦产量有着显著的正向效应,而5月和12月的SPI分别对东部、中北部地区的冬小麦产量有着显著的负向效应;西部地区冬小麦产量对关键月份气候干湿变化的响应更为敏感。

我国近20年主要粮食作物产量、进出口及化肥投入变化特征

为明确我国近年来主要粮食作物产量、进出口及化肥投入变化特征,基于中国统计年鉴数据,分析我国2000—2020年稻谷、小麦、玉米、豆类和薯类5种粮食作物的总产、单产、播种面积、进出口量及化肥投入的时空变化特征。结果表明:我国主要粮食产量在2003—2020年间连续17年递增,粮食总产的增加主要表现为东北、华北和西北农区玉米产量的增加。近20年5种粮食作物单产水平均呈上升趋势,以稻谷单产最高,但小麦单产提升幅度最高,为89.9%,稻谷单产提升幅度最低,为12.3%。与2000年相比,我国5种作物播种面积增加10.4%,总体上我国粮食播种面积和单产水平对粮食增产的贡献率分别为19.9%和80.1%。2000—2020年,我国稻谷、小麦、玉米和大豆4种作物进口量呈增加趋势,其中以大豆进口量最高,2020年占到4种粮食进口量的82.6%。我国化肥用量和施用强度均经历先增后减过程,峰值为2015年的6022.6万t。我国化肥用量主要集中在华北农区和长江中下游农区,年均化肥用量占全国年均投入量(5146.5万t)的55.1%,化肥施用强度则以东南农区和华北农区最大,分别较全国平均水平(322.6 kg/hm^(2))高66.4%和25.7%。综合上述,我国近20年主要粮食作物总产量整体呈增加趋势,粮食平均单产提高是我国粮食增产的主要贡献因子,我国粮食进出口由最初的调剂余缺转变为以大豆为主的大规模进口,化肥总用量以2015年为峰值经历先增后减变化规律。