Can soil organic carbon sequestration and the carbon management index be improved by changing the film mulching methods in the semiarid region?

Plastic film mulching has been widely used to increase maize yield in the semiarid area of China.However, whether long-term plastic film mulching is conducive to agricultural sustainability in this region remains controversial.A field experiment was initiated in 2013 with five different film mulching methods:(i) control method, flat planting without mulching (CK),(ii) flat planting with half film mulching (P),(iii) film mulching on ridges and planting in narrow furrows(S),(iv) full film mulching on double ridges (D), and (v) film mulching on ridges and planting in wide furrows (R).The effects on soil organic carbon (SOC) content, storage, and fractions, and on the carbon management index (CMI)were evaluated after nine consecutive years of plastic film mulching.The results showed that long-term plastic film mulching generally maintained the initial SOC level.Compared with no mulching, plastic film mulching increased the average crop yield, biomass yield, and root biomass by 48.38, 35.06, and 37.32%, respectively, which led to the improvement of SOC sequestration.Specifically, plastic film mulching significantly improved CMI, and increased the SOC content by 13.59%, SOC storage by 7.47%and easily oxidizable organic carbon (EOC) by 13.78%on average,but it reduced the other labile fractions.SOC sequestration and CMI were improved by refining the plastic film mulching methods.The S treatment had the best effect among the four mulching methods, so it can be used as a reasonable film mulching method for sustainable agricultural development in the semiarid area.

Improving maize growth and development simulation by integrating temperature compensatory effect under plastic film mulching into the AquaCrop model

Temperature compensatory effect, which quantifies the increase in cumulative air temperature from soil temperature increase caused by mulching, provides an effective method for incorporating soil temperature into crop models. In this study, compensated temperature was integrated into the AquaCrop model to investigate the capability of the compensatory effect to improve assessment of the promotion of maize growth and development by plastic film mulching(PM). A three-year experiment was conducted from2014 to 2016 with two maize varieties(spring and summer) and two mulching conditions(PM and non-mulching(NM)), and the AquaCrop model was employed to reproduce crop growth and yield responses to changes in NM, PM, and compensated PM. A marked difference in soil temperature between NM and PM was observed before 50 days after sowing(DAS) during three growing seasons. During sowing–emergence and emergence–tasseling, the increase in air temperature was proportional to the compensatory coefficient, with spring maize showing a higher compensatory temperature than summer maize. Simulation results for canopy cover(CC) were generally in good agreement with the measurements, whereas predictions of aboveground biomass and grain yield under PM indicated large underestimates from 60 DAS to the end of maturity. Simulations of spring maize biomass and yield showed general increase based on temperature compensation, accompanied by improvement in modeling accuracy, with RMSEs decreasing from 2.5 to 1.6 t ha^(-1)and from 4.1 t to 3.4 t ha^(-1). Improvement in biomass and yield simulation was less pronounced for summer than for spring maize, implying that crops grown during low-temperature periods would benefit more from the compensatory effect. This study demonstrated the effectiveness of the temperature compensatory effect to improve the performance of the AquaCrop model in simulating maize growth under PM practices.

Effects of plastic film mulching on soil greenhouse gases(CO2,CH4 and N2O) concentration within soil profiles in maize fields on the Loess Plateau,China

To better understand the effects of plastic film mulching on soil greenhouse gases（GHGs） emissions,we compared seasonal and vertical variations of GHG concentrations at seven soil depths in maize（Zea mays L.） fields at Changwu station in Shaanxi,a semi-humid region,between 2012 and 2013.Gas samples were taken simultaneously every one week from non-mulched（BP） and plastic film-mulched（FM） field plots.The results showed that the concentration of GHGs varied distinctly at the soil-atmosphere interface and in the soil profile during the maize growing season（MS）.Both carbon dioxide（CO_2） and nitrous oxide（N_2O） concentrations increased with increasement of soil depth,while the methane（CH_4）concentrations decreased with increasement of soil depth.A strong seasonal variation pattern was found for CO_2 and N_2O concentrations,as compared to an inconspicuous seasonal variation of CH_4 concentrations.The mean CO_2 and N_2O concentrations were higher,but the mean CH_4 concentration in the soil profiles was lower in the FM plots than in the BP plots.The results of this study suggested that plastic film mulching significantly increased the potential emissions of CO_2and N_2O from the soil,and promoted CH_4 absorption by the soil,particularly during the MS.

Better tillage selection before ridge–furrow film mulch can facilitate root proliferation, and increase nitrogen accumulation,translocation and grain yield of maize in a semiarid area

Plastic film mulch systems are used widely in arid areas, and the associated tillage measures affect soil properties, root and crop growth, and nutrient uptake. However, much debate surrounds the most suitable tillage method for plastic film mulch systems. We conducted a two-year field experiment to explore the impact of three tillage treatments-rotary tillage before ridge–furrow plastic film mulch(MR), no-tillage before ridge–furrow plastic film mulch(MZ), and plow tillage before ridge–furrow plastic film mulch(MP)-on soil total nitrogen, available nitrogen, root stratification structure,nitrogen transfer and utilization, and maize yield. The results showed that MP had better soil quality than either MR or MZ over 2019 and 2020, with higher nitrate-nitrogen and total nitrogen in the 0–40 cm soil layer. MP improved the soil physicochemical properties more than the other treatments, producing significantly higher root numbers and root biomass for the aerial and underground nodal roots than MR and MZ. At harvest, MP had the highest root biomass density,root length density, and root surface area density in the different soil layers(0–20, 20–40, and 0–40 cm). Significant correlations occurred between root biomass and aboveground nitrogen accumulation during maize growth. During grain filling, MP had the greatest nitrogen transfer amount, significantly increasing root and aboveground nitrogen transfer by 19.63–45.82% and 11.15–24.56%, respectively, relative to the other treatments. MP significantly produced 1.36–26.73%higher grain yields and a higher grain crude protein content at harvest than MR and MZ. MP also had higher values for the nitrogen harvest index, nitrogen uptake efficiency, and partial factor productivity of nitrogen fertilizer than MR and MZ.In conclusion, plow tillage combined with a ridge–furrow plastic film mulch system facilitated maize root development and improved nitrogen utilization, thereby increasing maize yield more than the other treatments.

Effects of plastic mulching film-induced leaf burning on seedling growth in tobacco cultivation:Different findings beyond conservation view

Solving high-temperature plastic mulching film-induced leaf burning in the first week during tobacco cultivation would take much time and effort. In the present study, the growth as well as the leaf sugar and nicotine contents of seedlings with or without leaf burning induced by high-temperature plastic mulching film were tested at two independent sites in 2015 and 2016 to identify the influence of leaf burning on seedling growth. The results showed that the growth of seedlings with leaf burning was improved with increased leaf area, leaf number and plant height compared to those without leaf burning, combined with an increased seedling survival rate at two sites in two years. In seedlings with leaf burning, the contents of fructose and glucose increased and peaked at 11：00 and 13：00 in the leaf and root, respectively, with an increased root nicotine content beginning at 13：00, highlighting the signalling role of sugars. Activities of antioxidant enzymes including peroxidase （POD）, superoxide dismutase （SOD） and catalase （CAT） were all increased in seedlings with leaf burning. More plant biomass was allocated to roots in seedlings with leaf burning with increased root volume compared to control seedlings, which might facilitate the absorption of water and nutrients from the soil. Our findings demonstrate that high-temperature plastic mulching film-induced leaf burning not inhibited but benefited seedling survival and growth, suggesting that the time and labour-consuming manual plucking of burnt leaves can be avoided during tobacco cultivation.

Mulching with plastic film improved the root quality of summersown sweet potato(Ipomoea batatas(L).Lam.)in northern China

The root quality of sweet potato cultivated during the summer season is poor in northern China;thus,this study was conducted to determine whether root quality could be improved through mulching with plastic film(MPF).The effect of MPF on root starch and its composition,the activity of starch synthesis enzymes,and other quality-related parameters were investigated in two purple flesh sweet potato cultivars,Jishu 18 and Ayamurasaki(Aya).The results indicated that root dry matter,anthocyanin content,adenosine triphosphate(ATP),and starch content were higher in both cultivars under the MPF treatment than those under the control treatment.The root adenosine diphosphate glucose pyrophosphorylase/uridine diphosphate glucose pyrophosphorylase(ADPGPPase/UDPGPPase)activity and adenosine triphosphatease(ATPase)activity were increased using MPF.However,under the MPF treatment,the amylose content,soluble sugar content,and granule-bound synthase(GBSS)activity increased in Jishu 18 but decreased in Aya,and the amylopectin content,protein content,and soluble starch synthase(SSS)activity decreased in Jishu 18 but increased in Aya.Therefore,MPF seems benifit to improve the quality of sweet potato,but the effects of this treatment condition may be dependent on the cultivar.

Cotton's Water Demand and Water-Saving Benefits under Drip Irrigation with Plastic Film Mulch

The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Field Observation and Research Station for Oasis Farmland Ecosystem in Aksu of Xinjiang in 2008.Water balance method was adopted to study the water requirement and water consumption law of cotton under mulched drip irrigation in Tarim Irrigated Area.Statistical analysis of experimental data of irrigation indicates that the relationship between yield of cotton and irrigation presents a quadratic parabola.We fit the model of cotton water production on the basis of field experimental data of cotton.And the analysis on water saving benefit of cotton under mulched drip irrigation was done.Results indicate that water requirements for the irrigated cotton are 543 mm in Tarim Irrigated Area.The water requirements of seedling stage is 252 mm,budding stage is 186 mm,bolling stage is 316 mm and wadding stage is 139 mm.the irrigation amount determines the spatial distribution of soil moisture and water consumption during cotton life cycle.However,water consumption at different growth stages was inconsistent with irrigation.Quantitatively,the water consumed by cotton decreases upon the increase of irrigation amount.From the perspective of water saving,the maximal water use efficiency can reach 3 091 m3/ha.But the highest cotton yield needs 3464 m3/ha irrigation water.In summary,compared to the conventional drip irrigation,a number of benefits in water saving and yield increase were observed when using plastic mulch.At the same amount of irrigation,the cotton yield with plastic mulch was 30.2% higher than conventional approaches,and the efficiency of water utilization increased by30.2%.While at the same yield level,29.3% water was saved by using plastic mulch,and the efficiency increased by 41.5%.

Effects of Plastic Film Mulching on Soil Carbon Fixation Capacity and Fertility Level in Eastern Qinghai

[Objectives]To explore the effects of single application of chemical fertilizers on soil carbon fixation capacity and soil fertility under plastic film mulching conditions in eastern Qinghai,and to provide a theoretical basis for realizing the sustainable development of film mulching planting method in this area.[Methods]The effects of single application of chemical fertilizer cultivation mode under film mulching conditions on the soil organic carbon(SOC),labile organic carbon(LOC),carbon management index(CMI),extractable humus carbon(CHE),humic acid carbon(CHA),and fulvic acid carbon(CFA)in the cultivated layer(0-20 cm)were studied through three consecutive years of field experiments on dryland maize farmland in the eastern Qinghai.[Results]Under the film mulching condition,the SOC,LOC and CMI of the single application of chemical fertilizer cultivation mode were lower than that of the open field control.CHE,CHA and CFA increased with the increase of planting years,but the degree of increase was generally less than that of the open field control.With the increase of planting years,by 2020,the soil LOC/SOC value of film mulching decreased by 4.97%compared with before the start of the experiment,while the open field control increased by 1.11%;the organic carbon oxidation stability coefficient(KOS)of the film mulching was higher than that of the open field control;the soil CHA/CFA value and PQ value were higher than that of the open field control.[Conclusions]Under the condition of single application of chemical fertilizers,the continuous film mulching cultivation mode reduces the soil carbon fixation capacity,and soil organic carbon tends to be stable,which is not conducive to biological utilization and could reduce the soil fertility and degrade the soil quality,causing adverse effects on the stability of crop yield and sustainable production in the long run.

Agronomic performances of biodegradable and non-biodegradable plastic film mulching on a maize cropping system in the semi-arid Loess Plateau,China

Biodegradable plastic film mulch (PFM) is considered an alternative to non-biodegradable PFM to mitigate the negative impacts of residual film.However,the agronomic performance of biodegradable PFM in comparison to non-biodegradable PFM still needs to be tested.In this study,we evaluated the effects of biodegradable and non-biodegradable PFM on soil physicochemical properties,microbial community,and enzyme activities,as well as maize growth performance.Biodegradable and non-biodegradable PFM both increased soil temperature,water content,N content,and microbial biomass and maize yield by up to 30%,but decreased soil enzyme activities as compared to no mulching (control,CK).Most soil physicochemical properties,microbial community,and enzyme activities were similar under non-biodegradable and biodegradable PFM at the early stages of maize growth.However,at the late stages,soil temperature,water content,mineral N,NO_(3)^(-)-N,ammonia monooxygenase (AMO) activity,and total phospholipid fatty acids (PLFAs) decreased under biodegradable PFM owing to film fragmentation.White PFM increased soil temperature,water content,and total PLFAs at the early stages of maize growth but decreased soil mineral N and total PLFAs at the late stages,as compared to black PFM.As soil temperature and N availability were the major factors affecting soil microbial community,microbial activity decreased after the fragmentation of biodegradable PFM,owing to the decreased soil temperature,water content,and mineral N.Notably,biodegradable PFM could decrease NO_(3)^(-)-N accumulation in topsoil by decreasing N transformation due to the lower microbial and N-related enzyme (e.g.,AMO) activities,compared with non-biodegradable PFM,which may avoid negative environmental impacts,such as NO_(3)^(-)-N leaching or gas emission after harvest.Maize yield,height,aboveground biomass,and N uptake under biodegradable PFM were similar to those under non-biodegradable PFM during maize growth,implying that biodegradable PFM has no negative impact on crop growth and yield.In general,biodegradable PFM was equivalent to non-biodegradable PFM in terms of maize yield increase and N uptake,but was environmentally friendly.Therefore,biodegradable PFM can be used as an alternative to non-biodegradable PFM in semi-arid areas for sustainable agricultural practices.

Effects of film mulching regime on soil water status and grain yield of rain-fed winter wheat on the Loess Plateau of China

Shortages and fluctuations in precipitation are influential limiting factors for the sustainable cultivation of rain-fed winter wheat on the Loess Plateau of China. Plastic film mulching is one of the most effective water management practices to improve soil moisture, and may be useful in the Loess Plateau for increasing soil water storage. A field experiment was conducted from July 2010 to June 2012 on the Loess Plateau to investigate the effects of mulching time and rates on soil water storage, evapotranspiration （ET）, water use efficiency （WUE）, and grain yield. Six treatments were conducted： （1） early mulching （starting 30 days after harvest） with whole mulching （EW）; （2） early mulching with half mulching （EH）; （3） early mulching with no mulching （EN）; （4） late mulching （starting 60 days after harvest） with whole mulching （LW）; （5） late mulching with half mulching （LH）; and （6） late mulching with no mulching （LN）. EW increased precipitation storage efficiency during the fallow periods of each season by 18.4 and 17.8%, respectively. EW improved soil water storage from 60 days after harvest to the booting stage and also outperformed LN by 13.8 and 20.9% in each growing season. EW also improved spike number per ha by 13.8 and 20.9% and grain yield by 11.7 and 17.4% during both years compared to LN. However, EW decreased WUE compared with LN. The overall results of this study demonstrated that EW could be a productive and efficient practice to improve wheat yield on the Loess Plateau of China.

不同种植方式对高寒旱区地膜小麦耗水特征和产量的影响

于2019—2022年在陇中高寒旱区以裸地条播为对照(CK),设置全膜覆土穴播(FM)和膜侧沟播(FS)两种覆盖方式,研究不同覆盖种植方式对冬小麦耗水特性、生长发育及产量的影响。结果表明:与CK相比,FM和FS处理播种期~拔节期0~20 cm土层土壤温度分别平均提高3.1℃和2.1℃,灌浆期分别降低0.6℃和1.0℃。覆盖能不同程度提高冬小麦各生育期0~200 cm土层土壤含水量,其中出苗期、返青期、拔节期和灌浆期提高幅度均高于20%。与CK相比,FM处理返青后冬小麦耗水量平均显著提高29.2%,返青前显著降低42.4%;FS处理返青期~灌浆期耗水量提高12.6%,返青前降低25.7%。各处理冬小麦基本苗、分蘖数、公顷穗数、穗粒数、千粒重和产量均表现为FM>FS>CK,处理间差异显著,其中FM和FS处理产量分别较CK平均提高74.7%和45.4%;处理间耗水量差异不显著;FM处理水分利用效率最大,较CK平均提高67.3%,FS次之,较CK平均提高46.1%。综上,地膜覆盖可调节土壤水分状况,改善冬小麦生长发育和成穗情况,显著提高产量和水分利用效率,其中全膜覆土穴播调节效应优于膜侧沟播,是适宜在高寒旱区地膜小麦生产中推广应用的种植方式。

我国典型区域农户地膜应用与回收处理行为的调查研究

地膜是我国重要的农业生产资料,其残留污染的有效防控对于促进我国农业绿色发展具有重要意义。农户是地膜残留污染防控的基本单元,其行为直接影响防控成效。本研究采用互联网发放调研问卷的方式,在我国新疆、山东和湖北3个地膜使用具有代表性的省(自治区),对农户的地膜购买、使用、回收和处理行为开展调研,共收集389份有效调查问卷;使用二元Logistic回归分析方法,进一步研究了影响农户回收与处理地膜的因素。结果表明:调研农户中有85.9%的农户地膜购买渠道为农资零售店,且购买时有68.3%的农户主要关注地膜质量,53.2%的农户关注地膜价格;调研农户中有64.5%的农户在购买地膜时通过其拉伸强度来判断质量,但只有49.5%的农户了解新国标对地膜厚度的规定。在新疆地膜主要用于棉花、瓜类和玉米,作物地膜覆盖率分别为96.3%、48.3%和96.0%;在山东地膜主要用于花生和瓜类,作物地膜覆盖率分别为72.9%和92.3%;在湖北地膜主要用于瓜类和烟草,作物地膜覆盖率分别为40.1%和100%。地膜使用的主要驱动因素为提高收入,在新疆还有增温与保水、在山东有增温、在湖北则有控草等差异化的因素。人工回收是3个省份主要的回收方式,残膜回收率超过80%的农户仅有45.7%,回收的主要影响因素为农户的生态环境保护意识。网点回收是主要的残膜处理方式,占47.8%;塑料对环境的影响和投入成本是影响农户残膜处理行为的主要因素。农户年龄、家庭人口和不回收是否会影响耕种在5%水平上显著正向影响农户的回收行为;学历为高中以上人数、农业收入、是否会受到处罚在5%水平上显著正向影响农户的处理行为,是否有回收网点在1%水平上显著正向影响农户的处理行为。研究表明,农资零售店是调研区域农户购买地膜的主要渠道,调研区域的主要覆膜作物为棉花、瓜类、玉米和烟草,人工回收是主要的回收方式,并主要通过网点回收进行处理。此外,3个省份农户对地膜的科学认知水平还有待进一步提高,学历、农业收入、监管和是否设置回收网点会显著影响农户的处理行为。

施氮对农用地膜表面微生物群落特征的影响

【目的】农用地膜表面是塑料降解菌筛选、动植物病原菌定殖及抗生素抗性基因富集的潜在热点区域,但地膜表面招募微生物的群落基本特征仍不明确,一定程度上限制了我们对地膜表面微生物定殖过程的理解。【方法】本研究基于地膜覆盖和施氮长期定位试验,2021年秋季采集覆膜当季的地膜样品,利用高通量测序分析了地膜表面的细菌与真菌群落特征。【结果】地膜表面细菌以蓝细菌门(Cyanobacteria)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)为主,而真菌以座囊菌纲(Dothideomycetes)为主。地膜及土壤表面均产生肉眼可见的绿色絮状微生物菌落,这说明了覆膜对地表微气候的改善有利于地衣系统的发育。施氮间接提高微生物群落α多样性,但不改变β多样性。同时,与对照相比,施氮增加了地膜表面细菌中芽单胞菌门(Gemmatimonadetes)相对丰度约160%,并分别提高了真菌中银耳纲(Tremellomycetes)和囊担菌纲(Eurotiomycetes)的相对丰度4.8倍和3.9倍。此外,地膜表面的细菌群落比真菌群落对施氮的响应更敏感。【结论】地膜表面是微生物的一个独特生境,施氮可间接影响地膜表面的微生物群落特征。

覆膜垄作对旱地雨养马铃薯田N2O排放的影响

旱地雨养马铃薯(Solanum tuberosum)田是一个重要的氧化亚氮(N_(2)O)排放源,是当前农业温室气体排放的研究热点之一。在马铃薯主粮化战略的推动下,马铃薯种植面积不断扩大,覆膜和垄作栽培是其中两种重要的种植方式,但其栽培下的马铃薯田N_(2)O排放规律尚不十分明确。选择内蒙古自治区武川县自然降水条件下的马铃薯田为试验对象,设置平作覆膜、垄作覆膜、平作不覆膜和垄作不覆膜4种处理,采用静态箱(暗箱)-气相色谱法监测N_(2)O的排放通量并分析其排放特征,运用实时荧光定量PCR技术(Real-time quantitative PCR,q-PCR)检测不同时期与N_(2)O排放相关的硝化菌和反硝化菌丰度,并测定相关的土壤要素,进而探究在覆膜和垄作条件下,影响雨养马铃薯田N_(2)O排放特性和规律的微生物机理。结果表明,雨养马铃薯田是N_(2)O排放源,其全生育期内平均N_(2)O累积排放量为N(0.47±0.08)kg·hm^(-2)。N_(2)O排放通量与土壤温度、水分含量之间具有显著的正相关关系(P<0.05)。在整个马铃薯生育期,氨氧化古菌(Ammonia-oxidizing Archaea,AOA)基本起到了控制N_(2)O排放的作用(P<0.05),而不是氨氧化细菌和反硝化菌。覆膜和垄作都可以直接或间接改变土壤物理性质使根际生态微环境发生变化,进而影响硝化菌和反硝化菌的活性,最终使N_(2)O排放发生变化。其中,覆膜垄作处理的N_(2)O累积排放量及排放强度最高,且垄作不覆膜处理的排放最少(P<0.05),累积量达到了0.401-0.515 kg·hm^(-2)。因此,从减排和不减产的角度来看,采用垄作不覆膜的种植方式效果最显著,旨在为旱地农业生产的可持续发展提供理论依据。

不同耕作方式与地膜覆盖对花生生理特性、产量及品质的影响

为优化花生栽培管理措施,进而提升花生产量和品质,本研究通过设置旋耕地膜覆盖(RTM),旋耕露地(RT),深耕地膜覆盖(DTM)以及深耕露地(DT)四个处理,系统研究了不同耕作方式和地膜覆盖对花生生理特性、产量及品质的影响。结果表明:深耕能够改善花生的光合性能,与RTM处理相比,DTM处理在2021年结荚期、饱果期和收获期的叶片净光合速率平均提高了2.57%;此外,深耕有利于花生干物质积累量的增加,与RTM处理相比,DTM处理累积干物质积累量在2021年提高了3.09%。地膜覆盖可以提高花生根系活力、叶片SPAD值、叶面积指数和净光合速率,延缓植株衰老,改善籽仁品质;与DT处理相比,DTM处理在2021年结荚期、饱果期和收获期的根系活力和叶面积指数分别平均提高了11.70%和13.40%。DTM处理与RTM、DT和RT处理相比,2022年荚果产量分别显著提高了5.72%、8.27%和13.08%。综上,深耕地膜覆盖可作为实现花生高产优质生产目标的有效措施。

陕北风沙草滩区覆膜对土壤理化性质和春玉米产量的影响

试验旨在探究覆膜方式对陕北风沙草滩区土壤理化性质和春玉米产量的影响。试验选取当地主推玉米品种中榆968,设置膜上栽培、膜际栽培和无膜栽培3个处理,分析覆膜对土壤含水量、pH值、有机质、玉米农艺性状、产量和籽粒营养品质的影响。结果显示,在0~20、21~40 cm土层,膜际栽培土壤含水量高于无膜栽培(P<0.05);在41~60 cm土层,膜上栽培和膜际栽培土壤含水量高于无膜栽培(P<0.05)。随着土壤深度的增加,各处理的土壤pH值均呈现下降趋势,不同土层的土壤pH值排序均为无膜栽培>膜际栽培>膜上栽培;其中0~20 cm土层膜上栽培土壤pH值低于无膜栽培(P<0.05)。在0~20 cm土层,膜际栽培与膜上栽培土壤有机质含量高于无膜栽培(P<0.05);41~60 cm土层膜际栽培土壤有机质含量高于膜上栽培和无膜栽培(P<0.05)。膜际栽培玉米的株高、鲜穗重、穗粒数和产量高于其他处理(P<0.05),茎粗和百粒重高于无膜栽培(P<0.05)。膜际栽培的玉米籽粒粗蛋白和粗脂肪含量为8.22%和4.58%,均高于无膜栽培(P<0.05)。研究表明,膜际栽培更适于陕北风沙草滩区的春玉米种植,可在该地进一步推广应用。

长期覆膜旱作和施用包膜尿素对水稻产量、氮肥利用率及土壤养分的影响

水稻覆膜旱作栽培(non-flooding plastic film mulching cultivation,PM)是以地膜覆盖为核心来实现水稻节水生产的综合集成创新技术。然而,在覆盖地膜后,氮肥只能在移栽前作为基肥一次性施用,导致水稻前期营养生长过盛和生育后期潜在缺氮,从而限制了水稻高产。聚合物包膜尿素(polymer coated urea,CR)是一种控释氮肥,在传统淹水栽培(traditional flooding cultivation,TF)模式下已成为提高作物产量和氮肥利用率的最佳管理措施之一,但尚未在PM模式下进行长期定位试验评估。本研究以高产中熟籼型杂交稻‘两优培九’为供试水稻品种,比较在PM和TF 2种栽培模式下施用CR和普通尿素(urea,UR)对水稻产量、氮肥利用率及土壤养分含量的影响。结果表明:与UR相比,在TF和PM模式下施用CR使水稻氮肥利用率分别提高9.2%和15.4%(P<0.05),使水稻产量分别提高8.6%和15.0%(P<0.05)。与TF模式相比,PM模式加速了土壤有机质的分解,降低了土壤全氮、碱解氮含量。与施用UR相比,在PM模式下施用CR能缓解土壤全氮、碱解氮含量的下降,并使经济效益提高16.8%。综上所述,施用CR是解决在PM模式下水稻生育后期缺氮问题的有效途径。

地膜覆盖艺机一体化栽培技术在高粱上的应用

干旱少雨和农村劳动力短缺严重限制了陕北旱区高粱产业发展和农民脱贫增收,推广应用地膜覆盖艺机一体化栽培技术以及引进筛选适合当地的配套品种是解决该问题的有效方法。以裸地栽培为对照,研究了7个高粱品种晋杂22、晋杂31、晋杂34、晋杂108、晋早5564、晋夏2842和晋中7742在地膜覆盖艺机一体化技术配套栽培下产量相关性状和收益的变化。结果表明,相比裸地栽培,覆膜艺机栽培显著提高了高粱的株高、穗长、千粒质量和产量,提高幅度分别为0.99%~12.64%、0.9%~7.3%、2.2%~12.9%、11.7%~32.6%;大幅度节省了人工成本,每公顷可节省约6 450元;增加了收益,增收幅度为103.6%~406.0%。其中,晋杂31的产量和收益最高,分别为10 346.7 kg/hm^(2)和16 943.4元/hm^(2),其次依次是晋杂108和晋杂34,产量分别为10 320.0、10 293.3 kg/hm^(2),收益分别为16 890.0、16 836.6元/hm^(2)。推荐晋杂31、晋杂108和晋杂34等3个高粱品种配套覆膜艺机栽培模式在陕北旱区推广种植。

覆膜砂质农田土壤水分和CO_(2)分布特征及玉米根叶衰老响应

干旱区新垦绿洲沙地灌溉强度大,农田覆膜后往往出现春玉米早衰现象。为探讨土壤水分和通气性是否是引发早衰的原因,本研究在河西走廊绿洲春玉米农田设置不覆膜(NM)和覆膜(PFM)处理,探求覆膜条件下土壤水分和CO_(2)分压(pCO_(2))对玉米根系生长、绿叶面积衰减、光合生理以及籽粒产量与品质的影响。覆膜处理中,覆膜区域的土壤pCO_(2)较未覆膜区域高40%以上;未覆膜处理中,对应区域的土壤pCO_(2)差异为13.9%~24.0%。相比不覆膜处理的对应区域,覆膜处理覆膜区域过高的土壤pCO_(2)使玉米花期根系活力下降19.7%,但非覆膜区根长密度和根系活力分别增加22.7%和9.6%。覆膜提高了春玉米拔节期叶片光合速率(20.0%)和蒸腾速率(8.5%),但抑制了花后叶片光合速率(−40.0%)和蒸腾速率(−18.0%);覆膜处理相对绿叶面积衰减启动时间和衰减最大速率时间分别提前1.7 d和7.1 d,而平均衰减速率和最大衰减速率分别增加6.7%和21.7%。覆膜的上述效应未显著影响玉米籽粒产量,但使籽粒淀粉含量和蛋白质含量分别降低20.1%和22.1%。以上结果表明,在干旱区新垦绿洲沙地,覆膜根区土壤pCO_(2)过高可能是导致玉米花后早衰和籽粒品质下降的重要原因,后期建议开展适时揭膜、控制灌溉(如亏缺灌溉、分根交替灌溉)或加气灌溉对覆膜新垦绿洲农田土壤通气性的改善研究。

马铃薯闽薯1号在仙游县种植表现与地膜覆盖栽培技术

马铃薯闽薯1号系龙岩市农业科学研究所与福建省农业科学院作物研究所共同选育的鲜食型马铃薯品种。2021—2022年在仙游县稻后作示范种植,表现长势旺、产量高与商品性好等特点。根据闽薯1号在仙游县稻后作的表现,针对地膜覆盖栽培的特点,从整地、种薯处理、地膜覆盖、科学施肥、合理灌溉、中耕培土、绿色防控、防冻减灾与适时收获等方面总结了仙游县稻后马铃薯的栽培技术。