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.

Effects of Different Plastic films Mulching on Soil Temperature and Moisture, the Growth and Yield of Sugarcane

[Objective] The effects of different plastic films mulching on soil temperature and moisture, and growth and yield of sugarcane were discussed in order to provide references for using different plastic film in sugarcane pro-duction. [Method]Four kinds of plastic films viz., normal colorless transparent plastic film, milky photodegradation weeding plastic film, black plastic film and gray-black plastic film were used in sugarcane cultivation by using no film mulching as the control. Soil temperature and moisture were measured during plastic film mulching period, and sugarcane agronomic traits such as emergence rate, tillering rate, plant hight, stalk diameter and effective stalk number were investigated during growth period, the cane yield and economic benefits were calculated during harvest period. [Result] The results showed that plastic film mulching could significantly increase soil temperature and moisture. Com-pared with the control, soil temperature was increased by 0.3-0.8 ℃ in three plastic films mulching treatment except for gray-black plastic film mulching. The soil moisture of all mulching treatments was 10.1%-17.4% higher than the control. Furthermore, the seedling emergence rate, tillering rate, effective stalk number and cane yield also could be improved using plastic film mulching,which were increased by 0.8%-9.9%, 20.6%-34.9%, 5190-10980 stalks/hm^2and6.4%-14.9% as compared to the control,while plant height and stalk diameter were found to be no significant effect by plastic film mulching. The results of benefit analysis indicated that, milky photodegradation weeding film mulching had the highest economic benefit, the second were normal colorless transparent plastic film mulching and black plastic film mulching, which were 5 987.2, 1 876.5 and 1 813.5 Yuan/hm^2 higher than the control. The gray-black film mulching treatment had poor benefit.[Conclusion] The milky photodegradation weeding plastic film could be vigorously extended in sugarcane production. Normal colorless transparent plastic film and black plastic film could be ex-tended gradually as a new kind of plastic film. The grayblack film should not be used for its higher cost and more thickness.

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.

Effects of Plastic Film Mulching on Physical Characters of Soil and Yield and Yield Components of Sweet Potato

Field experiments were carried out to study the effects of plastic film mulching on soil physical characters, including soil temperature, soil moisture content and soil bulk density, and yield and yield components of sweet potato. The results showed that plastic filming mulching increased soil temperature. Considering the soil temperature-increasing effect, the treatments ranked as black plastic film treatment 〉 white plastic film treatment 〉 control. However, with the deepening of soil layer, the warming effect of plastic film mulching was weakened. Black or white plastic film mulching was conducive to low T/R value, especially in the early growth stage of sweet potato. Plastic film mulching significantly improved the storage root yield of sweet potato. In terms of yield-improving effect, the treatments ranked as black plastic film treatment 〉 white plastic film treatment 〉 control. The storage root num- ber per plant showed a downward trend, but the weight of single storage root was increased.

Light Simplified Foxtail Millet Cultivation Technique Adopting Furrow Sowing beside Plastic Film Covering Micro-ridges

In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with the characteristics of low instable yield, manual thinning and weeding, high labor intensity, and labor and time saving, Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated furrow sowing beside plastic film covering micro-ridges, simplified cultivation and mechanized production, forming the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges. This study introduced the technique points of the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges, including preparation before sowing,sowing, attached agricultural machines, field management, harvest and residual film recovery.

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.

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.

Simulation of temperature distribution in double-row potato ridges mulched with plastic film covered with soil

In Northwest China,potatoes are cultivated on double-rows of each ridge which is mulched with plastic film,and the film is covered with some of soil.While effective in retaining soil moisture,this technique can render the potato seedlings prone to be burned if they are not released from the plastic film in time.In this study,the model of convective heat transfer of potato ridge under solar radiation and atmospheric radiation is established by the Fluent software.The processes of the heat transfer of potato ridge was simulated for a certain day,and the temperature distribution in the potato ridge was monitored over time.The temperature distribution of soil in the growth layer of potato plants was analyzed under different thickness and widths of the covering soil on the film.The results showed that with the increase of covering soil thickness and width,the time for soil at different depth to reach the peak-temperature was delayed,and the daily temperature change of soil where the different depths layer of potato plants growth was reduced.At that time,a binary regression equation of offset temperature was constructed by using the Response Surface Method.The best parameter combination for covering soil on the plastic film is a thickness of 50 mm and a width of 280 mm in the cold and arid areas of Northwest China.However,the offset temperature(PT)first decreased and then almost remained unchanged with the increase of covering soil thickness.Considering the operational efficiency and power consumption of soil covering devices in the field,the unchanged width of the covering soil is 200 mm.The field experiments have shown that a 50 mm thick of soil covering is beneficial for the growth of potato plants and a 200 mm width of soil covering is beneficial for the growth of potato plants.The height of potato plants was 21 cm,and the natural emergence rate of potatoes was 95.8%on June 9,2024.The environment of soil covered could provide theoretical support for the mechanized planting of potatoes.

Effects of mulch and planting methods on Medicago ruthenica seed yield and soil physical-chemical properties

Medicago ruthenica (L.) Trautv., a wild grass species, is commonly grown as a forage crop in arid and semi-arid areas of China. Herein, we explored mulch patterns and planting methods for optimizing M. ruthenica seed production in the loess plateau of the Gansu Province, China from 2017 to 2019. The experiments comprised of six treatments including (1) flat ground without mulch (F0, control);(2) flat ground with a transparent white 0.008 mm thick plastic film mulch (FP);(3) flat ground with 4500 kg/hm2 straw mulch (FS);(4) furrow with 10 cm ridges (R0);(5) furrow with plastic film mulch (RP);and (6) furrow with straw mulch (RS). Results showed that the harvested seed yield of M. ruthenica was the highest under RP treatment, followed by FP and FS treatments. Soil moisture content from mid-May to mid-August in 2017 was the highest under RP and FP treatments, followed by RS and FS treatments. In 2018, soil moisture content was the highest under RS and FS treatments. In 2017 and 2018, soil temperature was the highest under FP and RP treatments, followed by F0 and R0 treatments. Total and available nitrogen, phosphorus, and potassium contents were the highest under RS and FS treatments, followed by RP and FP treatments. Comprehensive analysis result showed that surface mulch improved soil microenvironment and increased seed yield of M. ruthenica. Straw mulch also effectively recycled excess crop straw, thereby encouraging the sustainable development of agriculture in this area. In conclusion, FS treatment was considered the best mode for M. ruthenica seed production in this area.

Design of New Farm Machine for Chopping Field Straw,Pressing it into Soil and Cleaning up Plastic Film

In this paper,we design a farm machine integrating the functions of chopping field straw,pressing field straw into soil,breaking stubble,and cleaning up plastic film,in order to improve the efficiency of plastic film cleaning,enrich the function of straw chopping equipment,reduce the noise generated at work,and further realize the intelligent harmony. The remote control button is used to control the work of the entire system,and the bluetooth remote control module and matrix keyboard are used to control the vehicle. With STM32 microcontroller as the main control chip,the machine controls the motion of the electric motor by relay,and employs LCD screen to realize real-time display of system work. It is convenient and easy to operate,with good human-computer interaction.

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。

Optimization of mechanized soil covering path based on the agronomic mode of full-film double-ditch with double-width filming

In order to further improve the working performance and efficiency of mechanized tillage operation of a full-film double-ditch seedbed,under the working conditions of different parameters of the spiral push-type soil covering device with double-width filming,the dynamic soil covering characteristics and soil covering uniformity of the device were analyzed,the collaborative and interactive coupling mechanism of the horizontal pushing process of the mulching soil and horizontally two-way spiral soil transmission device were revealed,and the main reasons for the influence of different soil covering belts on the change of soil particle number distribution were analyzed.Based on the full-film double-ditch mode with double-width filming,the mechanized soil covering path was optimized.In order to further reduce the disturbance on mulching soil by two-way spiral pushing,a kind of parallel shunt type soil covering device with double-width filming was designed,then a discrete element method was adopted to make simulation analysis and optimize the parallel shunt type soil covering device with double-width filming.Field verification tests showed that after the operation of the full-film double-ditch combined machine with double-width filming and soil covering installed with the parallel shunt type soil covering device,the qualified rate of the film edge soil covering width was 96.1%,an increase of 1.6%compared to that before optimization;the qualified rate of soil covering width at the center of the big ridge was 93.5%,an increase of 1.9%compared to that before optimization;the qualified rate of the soil covering thickness was 97.7%,an increase of 0.2%compared to that before optimization.The test indicators reached the requirements of relevant national and industrial standards,showing that the test results met the design requirements,and the working conditions of verification tests were consistent with the simulation results.

Degradability of biodegradable plastic films and its mulching effects on soil temperature and maize yield in northeastern China

Plastic film is an important resource in agricultural production,but it takes hundreds of years to degrade completely in natural environment.The large-scale use of plastic film will inevitably lead to serious environmental pollution.One way to solve the problem is to develop a substitutable mulching film,such as a biodegradable film that can ultimately be decomposed to water,carbon dioxide,and soil organic matter by micro-organisms.In this study,a 2-year experiment was conducted to determine the degradation properties of a biodegradable plastic film,including degradation rate,surface microstructure,tensile strength and elongation at break,and the effects of different mulching treatments on soil temperature and maize yield.The mulching experiment was conducted with three different biodegradable plastic films with different degradation rates,using a common plastic film and a non-mulched treatment as control.With the addition of the additives for degradation in the biodegradable plastic films,the degradation rates increased significantly,which were 7.2%-17.8%in 2017 and 18.1%-35.2%in 2018 after maize harvesting.However,the degradation occurred mainly on the ridge side.The decrease in tensile strength and elongation was proportional to the degradation rate of the degradable film.The SEM results indicated that the surface microstructures of the biodegradable films were loose and heterogeneous after maize harvesting.Biodegradable plastic film mulching increased the soil temperature at soil depths of 5 cm,15 cm,and 25 cm,over the maize’s entire growth period,by 3.1℃-3.2℃ in 2017 and 1.2℃-2.1℃ in 2018 compared with the non-mulched treatment.The biodegradable plastic film increased the maize yield by 10.4%-14.3%in 2017 and 11.6%-24.7%in 2018.The soil temperature and maize yield increases were statistically significant;however,with respect to maize qualities,there were no statistically significant increases among the five treatments.This study shows that biodegradable plastic film can be used as a substitute for common plastic film.However,the ingredients in biodegradable plastic films should be improved further to ensure that they can be degraded completely after crop harvest.

干旱地区不同颜色覆膜对土壤水热及茴香产量的影响

以“民勤2号”茴香为试材,采用大田随机区组设计方法,设置无覆盖(NM)、黑色地膜覆盖(BM)、透明地膜覆盖(TM)3个试验处理,测定了干旱区不同颜色覆膜下茴香农田土壤的含水量、温度、株高及产量,通过比较测定数据探究不同颜色覆膜对土壤水热及茴香产量的影响,以期为该地区茴香覆膜栽培技术应用提供参考依据。结果表明:覆膜可以提高茴香全生育期及不同土层土壤含水量,BM显著高于其他处理;不同生育期茴香农田土壤温度及不同生育期0~100 cm土层的土壤温度均表现为覆膜处理高于无覆膜处理,且BM>TM>NM;茴香株高、产量试验均表现为覆膜处理高于无覆膜处理,且BM增加效果最为显著。综上,覆黑色地膜在提高土壤含水量和土壤温度、增加茴香产量方面具有重要作用。

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。

地膜对花生土壤水热环境和生长的影响

【目的】研究不同可降解地膜与普通地膜对花生土壤水热环境和生长的影响。【方法】设置农用白色地膜(WM)、黑色地膜(BM)、白色全生物可降解膜(WDM)、黑色全生物可降解膜(BDM)及不覆膜(CK)共5个处理,开展大田试验探究不同颜色可降解膜和普通地膜覆盖对花生土壤水热环境及其生长的影响机制。【结果】(1)WDM处理与BDM处理较WM、BM处理增温保墒效果更好,苗期WDM处理0~25 cm土层平均土壤温度较WM处理高0.8℃,BDM处理较BM处理高0.6℃;苗期WDM处理夜间5 cm土层土壤平均温度较WM处理提高0.8℃,BDM处理较BM处理高0.6℃;苗期WDM处理夜间有效土壤积温较WM处理高88℃,BDM处理较BM处理高60℃;WDM处理全生育期土壤含水率较WM处理提高11.7%,BDM处理较BM处理提高7.2%。(2)WDM处理花生产量较WM、BM、BDM处理分别增加5.3%、6.6%、17.3%,WDM处理水分利用效率较WM、BM、BDM处理分别提高7.8%、11.7%、22.8%。(3)白色可降解膜较黑色可降解膜降解程度提高14.6%。【结论】综上可知,山东花生种植中适宜选用白色全生物可降解膜。

生物降解渗水地膜覆盖对旱作燕麦土壤酶活性及产量的影响

为探讨生物降解渗水地膜覆盖对黄土高原旱作区穴播燕麦土壤酶活性及产量的影响,于2021年开展了普通地膜、渗水地膜、生物降解渗水地膜3种类型地膜覆盖穴播燕麦研究,以不覆膜为对照(CK),分析不同类型地膜覆盖对旱作燕麦田间水热效应、土壤酶活性及产量的影响。结果表明,与CK相比,覆膜处理苗期地表土壤温度提高了0.04~4.98℃,显著(P<0.05)提高了0~40 cm土层土壤含水量;生物降解渗水地膜显著提高苗期土壤过氧化氢酶、脲酶活性以及成熟期蔗糖酶、脲酶活性,增幅11.03%~39.37%;在抽穗期,上述三种酶活性均达最大,生物降解渗水地膜覆盖处理0~20 cm土层土壤过氧化氢酶和蔗糖酶活性显著提高(增幅分别为0.82%和55.88%)。与CK相比,覆膜处理显著增加了燕麦籽粒产量和生物产量,总体表现为渗水地膜>普通地膜>生物降解渗水地膜>不覆膜,生物降解渗水地膜与普通地膜间无显著差异;生物降解渗水地膜较普通地膜覆盖节约成本1800元·hm^(-2)。综合考虑生态效益和经济效益,推荐在黄土高原旱作区应用生物降解渗水地膜穴播燕麦技术。

秸秆还田和覆膜对旱作雨养农田土壤理化性质及春玉米产量的影响

【目的】研究干旱区不同秸秆还田方式与覆膜处理对农田土壤水分和养分含量及春玉米产量和水分利用效率的影响,分析不同秸秆还田方式的农田培肥和增产效应,筛选西北旱区绿色高效的秸秆资源化利用方式,为旱区农业高质量发展提供科技支撑。【方法】于2019~2020年在甘肃省会宁县设计大田试验,设置秸秆不还田+无膜(CK)、秸秆粉碎还田(SS)、秸秆发酵还田(FS)、秸秆不还田+覆膜(MK)、秸秆粉碎还田+覆膜(MS)和秸秆发酵还田+覆膜(MFS)6个处理,测定不同秸秆还田与覆膜处理下土壤水分含量、贮水量和耗水量、土壤碳氮磷钾、作物水分利用效率、干物质累积量和产量。【结果】2种覆膜处理下,秸秆还田可使全生育期耕层贮水量增加7.33%~16.29%,水分利用效率提高10.73%~19.25%,其中,秸秆发酵还田的耕层贮水量和水分利用效率较秸秆粉碎还田平均增加了6.39%和7.38%。覆膜处理可进一步提高土壤贮水量和水分利用率,增幅分别为10.62%~16.29%、13.88%~18.87%;并增加了土壤养分含量,其中土壤有机碳、全氮、碱解氮、速效磷和速效钾含量分别增加0.70%~8.03%、1.63%~8.01%、7.75%~13.86%、9.19%~40.48%和4.06%~10.62%。与秸秆还田或覆膜相比,秸秆还田结合覆膜处理的干物质量和产量分别增加3.10%~15.35%、11.02%~17.08%,1.84%~12.81%、8.94%~14.83%;其中秸秆发酵还田增加最多,平均为12.04%和10.08%。【结论】秸秆还田和覆膜通过调控土壤水分和养分,提升了土壤供水供肥能力,进而促进作物干物质积累量和产量的同步增长。其中秸秆发酵还田(MFS)效果优于粉碎还田(MS),有利于春玉米抗旱、增肥、增效和高产。

不同覆盖方式对旱地冬小麦土壤水热及光合特性的影响

为了探明不同覆盖方式对旱地冬小麦土壤水热、光合特性的影响,在陇中半干旱区,设置了露地无覆盖(CK)、秸秆带状覆盖(SM4、SM5)和地膜覆盖(PM),对不同处理下小麦田土壤水热状况、叶片光合指标和产量进行测定与分析。结果表明,与CK比较,SM4、SM5和PM处理均显著增加了冬小麦播种至收获期的土壤平均含水量,增幅分别为7.0%、9.0%和8.5%;SM4和SM5处理显著降低了冬小麦全生育期土壤平均温度,降幅分别为11.3%和13.7%,而PM处理显著增加了全生育期土壤平均温度,增幅为6.7%;SM4、SM5和PM处理使小麦净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))分别增加了16.3%、18.4%、2.6%,17.2%、19.2%、8.9%和26.0%、30.7%、8.9%,使胞间CO_(2)浓度(C_(i))分别降低7.2%、9.1%和3.1%,SM5处理较SM4处理的变幅更大。与CK相比,SM4、SM5、PM处理显著增加了冬小麦籽粒产量和生物产量,增幅分别为11.9%、18.0%、20.9%和16.7%、19.0%、25.5%。相关分析表明,冬小麦籽粒产量与旗叶P_(n)(r=0.539*)和T_(r)(r=0.633*)呈显著正相关;冬小麦开花期和灌浆前期旗叶光合生理特性对籽粒产量和千粒重的影响大于灌浆后期。可见,在旱地小麦种植中,秸秆带状覆盖能显著改善土壤水热情况,提高旗叶光合能力,使小麦产量显著增加。