Residual Effects of Phosphate Amendments on Rainfed Rice (Oryza sativa L.) Nutrition and Soil Properties in Three Agroecological Zones of Côte d’Ivoire

A study was conducted in Côte d’Ivoire to assess the after-effect of phosphate amendments on rice yields and soil properties. Eight types of amendments, composed of Moroccan phosphate rock (PRM) and triple superphosphate were tested in three agroecological zones over three consecutive years of cultivation. This study revealed that the application of Moroccan phosphate rock (PRM) and/or triple superphosphate (TSP) did not significantly affect soil cation exchange capacity (CEC) and organic carbon (Corg) content. However, there was a negative residual effect of PRM-rich treatments on soil pH and K and N content, but the impact varies depending on the characteristics of the soils studied. Furthermore, nutrient losses, notably nitrogen from −17.5 to −267.7 kg/ha and potassium (−0.1 to 0.7 kg/ha), were observed in all treatments. Only phosphorus showed a positive balance of +49.56 to +52 kg/ha in PRM-rich treatments. Treatment T3, composed of 80% RPM and 20% TSP, was the most effective in all zones, with a relative increase in grain yields of over 100% compared to the control. These results suggest that the input of natural phosphate rock can significantly improve rice yields and soil properties in the studied agroecological zones in Côte d’Ivoire.

Is the crop insurance program effective in China? Evidence from farmers analysis in five provinces

This paper aims to evaluate the effectiveness of the Chinese crop insurance program in terms of farmers＇ utility and welfare. A simulation model based on the power utility function was first developed to evaluate the effectiveness of crop insurance. Then, the Monte Carlo approach was used to generate the datasets of area, price, yield, cost, and income based on the characteristics of representative farmers, which were clustered and calibrated using the farm-level data of 574 individual farmers from five Chinese provinces. Finally, the effectiveness of Chinese crop insurance was evaluated by comparing the certainty equivalence（CE） of farmers＇ utility/welfare under alternative crop insurance scenarios. Government subsidy is a necessary premise for implementing the crop insurance program. The government should subsidize more than 50% of the crop insurance premium to motivate more farmers to participate in the program. The findings also show that the current crop insurance program in China has increased the farmers＇ welfare but still need to be improved to achieve the Pareto improvement and to make full use of the financial fund of the government. This paper is believed to not only extend academic research but also has significant implications for policymakers, especially in the context of rapid development of Chinese crop insurance with much issues such as rate, subsidy and coverage level needed to be improved.

基于AquaCrop模型的玉米需水和降水匹配度变化特征研究

雨热同期为我国大部分地区农业生产提供了充足的水热资源,但从需水机理的角度评估作物生长和降水过程匹配度的变化特征还有待深入。基于AquaCrop模型模拟了关中地区1978-2017年夏玉米生育期内需水量、灌溉需水量、有效降水量和产量的变化特征,并在充分考虑玉米不同生育阶段对水分需求程度差异的基础上,分析了作物需水与降水匹配度的变化特征。结果表明:关中地区玉米生育期内累积降雨量变化幅度相对较小,但降水过程明显后移,且更多的以暴雨的形式发生;玉米生育期内需水量和灌溉需水量均呈现明显的增加趋势,增加幅度分别为4.10 mm/10a和13.38 mm/10a,而有效降水量则以-10.28 mm/10a的速率减小;玉米生育期内需水与降水的平均匹配度为58%,且整体以-2.7%/10a的速率下降。上述结果表明关中地区降水模式越来越难以满足夏玉米的水分需求,延迟播种可作为提高作物需水与降水匹配度的应对措施之一。

Construction of Transgenic Crop Germplasm Effective Function and Characteristic Analysis

Germplasm effect reflects the quantitative relation between production ability of germplasm elements and yield （quality） of a certain crop, which can be shown by mathematic function, namely, germplasm effect function. Germplasm effect of a crop variety is an aggregation of many effective factors, and is restrained by different effective factors; constant increase of any one effect of germplasm elements would lead to law of effect decline, therefore, possible modes of transgenic crops effect function were deduced according to the law of effect decline. The possible modes of single transgenic germplasm effect function and multi-transgenic germplasm effect regression equation were discussed, and the characteristics of germplasm effect regression equation were analyzed in this paper.

Residual Effect of Biochar on Soil Properties and Yield of Maize (<i>Zea mays L.</i>) under Different Cropping Systems

A field experiment was conducted to examine the residual influence of biochar applied previously to an established experiment at the Agriculture University Research Farm, Peshawar on soil properties and yield of maize crop during summer 2016. The experiment was established in RCB design with split plot arrangements having cropping systems (CS) in main plots and biochar (BC) in sub-plots. Cropping systems were: 1) wheat-mung bean;2) wheat-maize;3) chickpea-maize;and 4) chickpea-mung bean. During the past three seasons, each cropping system received biochar at 0, 40, 60 and 80 t&#183ha&#451 along with recommended dose of NPK in each season. For this study, maize was planted after chickpea and wheat in summer 2016. The results showed that grain yield, cobs weight and total N uptake of maize was significantly greater for chickpea-maize than for wheat-maize cropping system. Soil organic C was also significantly higher in soil under chickpea-maize than under wheat-maize cropping system. However, other yield components such as stover yield, harvest index and N concentration in grain and stover of maize and soil properties such as pH, EC and mineral N were non-significantly affected by cropping systems. With respect to residual effect of biochar grain yield of maize and bulk density of soil were maximum for treatment receiving biochar at 40 t&#183ha&#451 whereas cobs weight soil pH and mineral N were highest receiving biochar at 60 t&#183ha&#451. Moreover, N concentration in stover, N uptake and soil organic C were maximum for treatment receiving biochar at 80 t&#183ha&#451. However, stover yield, harvest index, N concentration in grain, and soil EC were non-significantly affected by biochar treatments. However interactions between CS × BC were significant for yield and yield parameters of maize and for soil properties (bulk density mineral N), while non-significant for harvest index, soil organic C, pH and EC. It was concluded that chickpea-maize cropping system performed better in terms of improving yield and yield components of maize and in improving soil properties. Application of biochar to previous crops also improved yield and yield parameters of the following maize as well as soil properties. Thus we recommend that legumes must be involved in cropping system for sustainable and higher productivity and improved soil properties. However, further studies are suggested to find out suitable dose of biochar for sustainable and economic crop productivity and soil fertility.

Effects of simulated acid rain on the injury and physiological responses of crops

Experiment was performed to determine the injury and physiological responses of plantfoliage to simulated acid rain. Cross section of injured leaves, PH value of foliar homogenate,electrolyte leakage, malondialdehyde content, content of peroxidase and some other enzymes were exa-nilned after exposure to simulated acid rain. Plants exhibited visible leaf injury when exposed tosimulated acid rain at PH values of 2.5 and 3.0. Peroxidase content and isozyme bands increasedsignificantly after the treatment at PH 3.0. Injured plants had higher electrolyte leakage and higherlevels of malondialdehyde. This showed that simulated acid rain induced lipid peroxidation andmembrane damage.

Present Development Situation of Transgenic Crops and Effect on Ecological Environment

The present development situation of transgenic crops and their effect on ecological environment are introduced in the paper. Some relevant strategies for their future and how to control the risks of ecological environment are presented.

The Mathematical Analysis on the Risk Management Effect of Crop Insurance Plan

As a variant index, variation has an inherent shortcoming that it can only reflect the static fluctuation of the crop. This paper makes complementary analysis about it on the basis of the comment on Miranda＇s approach of β index and goes on to analyze the β index approach under the condition of three kinds of crop insurance plans, β index approach has the advantage that it can dynamically reflect the risk transfer effect of crop insurance plan. At the same insurance level, the smaller the β index is, the better the corresponding risk transfer effect of crop insurance plan is; And vice versa.

农业废弃物基生物炭的应用效应研究进展

生物炭因结构和理化性质独特、原材料丰富及应用前景广阔等特点,在农业及环境污染治理等领域的应用较为广泛。基于相关文献,综述了农业废弃物基生物炭在改善土壤理化性质、提高土壤养分、改善土壤微生态环境、促进作物生长、修复污染土壤及缓解连作障碍等方面的效应,旨在为农业废弃物基生物炭在农业生产中的应用提供参考。

土膜耕作法的土壤与作物效应研究

【目的】探索土膜耕作法对农田土壤水分、温度和养分变化的影响,揭示土膜对作物根系生长及产量效应,明确土膜的农业生产价值,为其应用提供理论依据与技术。【方法】在宁夏引黄灌区通过喷施1.0%浓度羧甲基纤维素铵(carboxymethyl cellulose ammonium,CMC-NH4)水溶液促使土膜产生。设CMC-NH4用量0(CK)、50.0(T1)、100.0(T2)、200.0(T3)和300.0 kg·hm^(-2)(T4)5个处理,开展春小麦-夏玉米复种下的土壤水分、温度、养分、微生物、作物根系及产量效应研究。【结果】喷施CMC-NH4的各处理春小麦和夏玉米田土壤日均含水量提高3.3%—7.0%(P<0.05,下同)和1.9%—6.1%,日平均温度提高7.9%—12.6%和5.6%—11.7%,土壤积温增加88.98—141.94℃和60.25—136.65℃;0—30 cm土层根长提高37.5%—17.1%和11.2%—1.7%,根表面积提高15.3%—4.5%和12.5%—9.2%,土层根系干重增加17.0%—41.5%和30.9%—36.7%;提高春小麦籽粒产量7.3%—18.8%和夏玉米地上部干重33.6%—49.0%,提高土壤氮磷钾含量和促进土壤微生物多样性增加。【结论】喷施CMC-NH4形成的土膜具有农田覆盖功能,能够改善土壤水热环境,促进作物养分吸收利用、根系生长、提高产量;土膜耕作法为构造“表实上虚下实”良好耕层结构提供了技术方法,对作物产能提升、农田土壤改良及农业高质量发展有支撑作用。宁夏引黄灌区CMC-NH4推荐喷施量为100.0 kg·hm^(-2)。

数字经济发展对种植业碳排放效率的影响研究——基于中介和门槛效应的实证检验

农业源温室气体排放量(碳排放)仅次于工业,种植业作为农业的基础,其碳排放量在农业中占据较大比重,种植业碳减排对于“双碳”目标的实现具有重要意义。在“碳达峰、碳中和”的碳排放格局下,数字经济已成为推动种植业绿色低碳高质量发展的新引擎。本文在理论探讨基础上,结合2011—2021年中国31个省(自治区、直辖市,不包括中国香港地区、澳门地区和台湾地区)面板数据,综合利用固定效应回归模型、工具变量模型、中介效应模型、门槛效应模型,实证考察了数字经济发展与种植业碳排放效率之间的内在关系。研究发现,数字经济发展对种植业碳排放效率具有显著的正向影响,且存在农业生产功能与区域异质性;数字经济发展通过促进技术创新和规模经营来抑制种植业碳排放,且“技术创新效应”的贡献份额大于“规模经营效应”;数字经济发展对种植业碳排放效率的促进作用还受经济发展水平的影响,当经济发展水平低于阈值时,数字经济发展对种植业碳排放效率的影响并不显著,当经济发展水平超过阈值后,数字经济发展能够对种植业碳排放效率产生显著的提升效应。

黄河中下游地区耐旱作物扩种的节水降碳协同效应评价

为应对黄河流域农业可持续发展面临的气候变化和水资源短缺挑战,通过推广种植耐旱作物,缓解区域农业用水压力,并分析其节水降碳协同效应,研究设计了趋势照常、缓慢增长、技术引导、政策扶持等不同发展情景,制定了小麦、玉米、高粱、马铃薯4种耐旱作物扩种的节水降碳协同效应分析方案;采用农业节水潜力修正模型和农业降碳潜力模型定量评估了不同情景下耐旱作物扩种的节水效应及降碳潜力。结果表明:黄河中下游地区小麦和玉米的种植面积最大,高粱和马铃薯则相对较小,在政策扶持情景下,2060年小麦、玉米、高粱、马铃薯的扩种规模分别为23.12万、17.34万、34.68万、40.45万hm^(2)。在技术引导和政策扶持情景下,黄河中下游作物的节水效应和降碳效应均显著提升,2060年该区总节水量达153.52亿m^(3)、降碳潜力的平均水平达65.93 t/km^(2)。在黄河中下游地区推广耐旱作物有助于缓解水资源短缺状况,保障区域粮食安全,实现节水降碳增收多重目标。

生物质缓释土壤保水增肥剂对宁夏盐池县土壤及其作物的影响

为探讨生物质缓释土壤保水增肥剂对农田土壤水温环境、土壤养分吸收和作物产量的影响,在宁夏回族自治区吴忠市盐池县以玉米、马铃薯、燕麦等为供试作物,生物质缓释土壤保水增肥剂为供试材料,采用田间试验,设置生物质缓释土壤保水增肥剂不同梯度的施用量,测定土壤含水量、酸碱度、电导率、容重和土壤养分等,研究其对试验地区土壤理化性质、土壤养分以及不同作物产量的影响。结果表明:在施用量不同的情况下,所种植的作物总体上产量都有所增加。苏丹草和燕麦草增产率最高,分别达到36.26%和24.35%。荞麦在生物质缓释土壤保水增肥剂施用量为120kg/hm^(2)时产量增产率达到23.19%,而马铃薯在生物质缓释土壤保水增肥剂施用量为120kg/hm^(2)时产量增产率最高,达到了77.78%,增产效果显著。但玉米产量变化趋势有所不同,在生物质缓释土壤保水增肥剂施用量为60kg/hm^(2)时产量反而有所下降,当施用量增加至120kg/hm^(2)时产量有所上升,但增产率只有0.69%,主要是由于地块所处位置、地势以及土壤组分存在一定程度的差异性,导致生物质缓释土壤保水增肥剂施用量对玉米产量影响不大。

生物质炭调控药用植物连作障碍的研究进展

我国是中药材种植大国,但不合理的栽培方式和管理措施导致中药材连作障碍在种植区普遍存在,造成药材减产变质、道地产区转移、资源保护与利用不协调等,严重影响药用植物生长发育。因此对中药材连作土壤进行修复是解决中药材连作障碍的一个关键措施。生物质炭一般呈碱性,是一种良好的土壤改良剂,能够增加土壤养分、改良酸化土壤、提升植物品质,近年来得到广泛关注与应用,因此利用生物质炭作为调理剂来缓解中药材连作障碍具有一定潜力。本文针对我国中药材连作障碍的可能成因及潜在危害,分析生物质炭在解决药用植物连作造成的土壤理化性质改变、土壤微生物区系改变、化感自毒危害等问题上的作用,并对生物质炭在药用植物生产上的应用潜力进行展望。

1963—2022年气候变化对黑龙江省大豆需水量的影响

为揭示黑龙江省气候变化对大豆需水量的影响,基于61个气象站1963—2022年逐日气象数据和20个农业气象观测站1993—2013年大豆生育期资料,利用五日滑动平均法、单作物系数法、ArcMap空间分析、MATLAB计算和Mann-Kendall趋势检验法,计算并绘制≥10℃活动积温、大豆不同品种熟型交替变化下的需水量、有效降雨量、需水量与有效降雨量耦合度及三者气象倾向率的分布图。结果表明:(1)1963—2022年黑龙江省≥10℃活动积温呈增加趋势,1993—2002年是活动积温快速增长转折期,划定1973—1992年为积温平缓增长期,1993—2022年为积温快速增长期。不同熟型大豆种植边界线北移东扩明显。(2)1963—2022年黑龙江省大豆生长季内有效降雨量为377 mm,呈增加趋势,空间分布上由西向东表现为先增加后减少;需水量为312 mm,以-3.14 mm·10a^(-1)的平均速率下降,空间分布上由西向东呈减少趋势。(3)1963—2022年黑龙江省大豆生长季内需水量与有效降雨量的耦合度总体呈增加趋势,泰来县增加最明显;北部部分地区呈减少趋势,加大对水资源的消耗。(4)气象因子中温度和降雨量显著上升,日照时数和风速显著下降,使得大豆需水量下降、需水量与有效降雨量的耦合度上升,有利于缓解大豆种植区干旱。

广西荔浦市土壤—农作物中重金属迁移转化及生态效应

为了解荔浦市土壤和农作物中重金属含量及其分布特征,采集荔浦市土壤及农作物(水稻、荔浦芋、柑橘、马蹄)样品,测定土壤样品pH值、As、Cd、Cr、Hg、Ni、Pb、Cu、Zn全量以及As、Cd、Cr、Hg、Pb的形态含量,农作物样品测定了As、Cd、Cr、Hg、Pb含量,计算出重金属元素的生物富集系数(BCF),探讨了土壤—农作物系统中重金属元素迁移转化和生态效应。结果表明:(1)区内表层土壤以酸性土壤为主,As、Cd、Cr、Hg、Ni、Pb、Cu、Zn平均含量分别为13.57×10-6、0.33×10-6、87.06×10-6、0.153×10-6、27.49×10-6、30.46×10-6、27.94×10-6、82.53×10-6,均高于全国土壤背景值。(2)农作物中水稻样品中的重金属含量较荔浦芋、柑橘、马蹄中高,且水稻根、茎、籽实中重金属含量也不同。(3)重金属元素的生物富集系数在水稻中普遍偏高,水稻根部生物富集系数最大,籽实最小。重金属在土壤—水稻系统的迁移能力显著高于荔浦芋、柑橘和马蹄。(4)Cd是研究区最活跃的土壤重金属元素,其可交换态占全量比例显著高于As、Cr、Hg、Pb,应重点关注Cd的生态风险情况,防止农作物Cd超标对人类产生危害。

农田土壤有效态镉的分析方法筛选与优化

【目的】准确测定污染农田土壤中镉(cadmium,Cd)的有效态含量,并高效预测农作物可食部分的Cd含量。【方法】基于原始碳酸氢铵—二乙三胺五乙酸(ammonium bicarbonate-diethylenetriamine pentaacetic acid,AB-DTPA)浸提法,运用正交试验法对浸提剂pH、加入量及浸提时间3种提取条件进行正交组合,筛选最优条件,确定优化方法。采用野外采样和室内盆栽2种方式,对土壤—作物系统中Cd的迁移效应进行拟合验证。【结果】优化AB-DTPA法提取土壤有效态Cd的最佳条件为:提取剂加入量50 mL,pH 7.0,振荡时间60 min。优化AB-DTPA法提取的土壤有效态Cd含量对作物可食部分Cd吸收量的预测效果最佳。优化AB-DTPA法提取Cd元素测定结果的相对标准偏差均小于20%,加标回收率为100.00%~115.00%。【结论】优化后的AB-DTPA法适用于分析污染农田土壤中Cd的有效态含量,并预测农作物可食部分吸收的Cd含量,具有可行性、广泛适用性和准确性,能满足有效态Cd的批量分析要求。

灵武农场秋播小黑麦后复种青贮玉米的种植效果分析

为有效缓解灌区饲草产量低、栽培技术落后、季节性青饲料极其短缺造成的草畜发展极不平衡现状,2020—2022年,经过小黑麦复种青贮玉米田间示范,初步探讨宁夏回族自治区引黄灌区新型牛羊饲草生产模式的可行性。结果表明,二者可进行上下茬搭配,形成复种,可实现饲草周年生产。小黑麦复种青贮玉米模式下饲用小黑麦及青贮玉米品质均达到饲用标准,同时饲用小黑麦干草产量10.5 t/hm2,青贮玉米产量54 t/hm2,综合效益较春种玉米高8 055元/hm2。该模式下饲草生物产量及品质均较高,在宁夏引黄灌区可进行推广。

作物根际激发效应:调控农田土壤碳动态及助力碳中和的关键因素

土壤碳是陆地碳库的重要组成部分,碳输入及输出、矿化与固定的动态平衡是实现碳中和的关键因素。根际激发效应(rhizosphere priming effect,RPE)是指活体植物的存在会显著影响植物-土壤系统碳动态,其微小变化都会影响宏观尺度上的土壤-大气碳动态。因此,作物RPE是调控农田土壤碳动态和碳中和的主导因子。本文通过文献回顾,首先阐述了农业实践过程中各种生物因素和非生物因素对作物RPE影响的研究现状;其次,归纳总结了当前作物RPE研究中的热点、难点,并分析其对土壤碳排放调控的意义,阐明了当前研究普遍存在案例特异性且缺乏普遍规律;最后,基于已有的研究提出农田生态系统中土壤碳调控和管理优化的潜在策略,为农业实践中有目的地调控作物RPE,在田间、种植模式及区域尺度上提出可能的方案指明了方向。本文可为生态农业实践中保障粮食安全的同时助力碳中和这一双赢方案提供理论参考。

砜吡草唑与丙炔氟草胺对杂草的联合作用及玉米安全性评价

为筛选出有效防除玉米田杂草的除草剂混剂配比及其作物安全性,采用室内盆栽法测定了砜吡草唑与丙炔氟草胺及其不同比例混配组合对杂草生长的抑制作用及玉米安全性。结果表明,砜吡草唑与丙炔氟草胺不同比例的混配组合对稗草、马唐和藜均表现出加成作用,其中砜吡草唑与丙炔氟草胺质量比为1.25~20∶1时加成作用更为明显。砜吡草唑与丙炔氟草胺质量比为1~20∶1时,其在供试玉米品种和杂草之间的选择性指数较高,对玉米作物安全。