Influence of Diazotrophic Bacteria on Antioxidant Enzymes and Some Biochemical Characteristics of Soybean Subjected to Water Stress

Drought stress is an abiotic stress that imposes serious constraints on plants. The present investigation was carried out to determine the inter-relationship between some physiological attributes of soybeans affected by drought stress and pure isolates ofAzotobacter andAzospirillum. Drought stress and bacterial application increased catalase and glutathione peroxidase activity, whereas drought stress increased superoxide dismutase activity during the pod-filling stage. Abscisic acid and proline levels increased due to drought stress and bacterial application during the flowering stage, whereas total plant nitrogen was enhanced under well-watered conditions when plants were inoculated with bacteria. The close relationship between enzyme activity and drought stress with bacteria indicated that antioxidant enzymes play an important role in alleviating the detrimental effects of water stress. In addition, the enhancement of abscisic acid and proline could be positively linked with drought stress, and drought-induced abscisic acid could induce proline accumulation and the expression of antioxidant enzyme genes.

Influence of Soil Water Deficit and Phosphorus Application on Phosphorus Uptake and Yield of Soybean (<i>Glycine max</i>L.) at Dejen, North-West Ethiopia

A green house experiment was conducted at Dejen, Northwest Ethiopia, with the objective of quantifying the critical soil water deficit and P levels that affect yield and yield components of soybean, and determine the critical soil water deficit levels influencing P uptake in soybean. The treatment consisted of factorial combination of four available soil water (ASW) deficit levels (0%, 25%, 50% and 75%) and four levels of phosphorus (0, 10, 20, and 30 kg·ha-1) laid out in RCBD with four replications using soy bean variety Jalale as a planting material. The experiment was conducted under green house condition at Dejen, South Ethiopia during the 2011 academic year. Air dried soil was filled in the pots and seeds were sown on May 13, 2011. Four plants were maintained on each pot after thinning till flowering but after flowering, the total number of plants per pot was reduced to three as one plant which was used for measurement of root biomass. The water deficit treatments were imposed after the plants have been fully established 2 weeks after emergence just before branching stage. The water deficiency was imposed through maintaining the soil moisture content below field capacity at the deficit levels of 25%, 50% and 75%. The 75% of ASW deficit resulted in the longest days (45) to flowering and maturity (99) compared to the 0%, 25% and 50% deficit levels. Also, the 75% of ASW deficit level resulted in shorter plants (55 cm), the lowest leaf area (82.6 cm2), the highest root to shoot ratio (0.0168) and the lowest DM accumulation (161.3 gm-2) compared to the other ASW deficit levels. Likewise, the 75% of ASW deficit level gave the lowest number of pods per plant (4.13), seeds per pod (1.69), 100 seed weight (2.54 g), seed yield (13.4 g·m-1), above ground biomass (174.6 g·plant-1) and harvest index (0.08) compared to the other ASW deficit treatments. The degree of sensitivity to drought increased dramatically (from 0.0423 at 25% to 0.9604 at 75%) with increase in water deficit level. Tissue analysis results indicated that the highest seed P concentration (1.285%) and uptake (432.5 g·plant-1) were obtained at the 0 ASW deficit and 30 kg·P·ha-1 and the lowest were obtained at 75% ASW deficit and all rate of applied P. On the contrary, the highest straw P concentration (1.88%) and uptake (552.7 g·plant-1) were recorded at 75% and 25% of ASW deficit levels and 30 kg·P·ha-1, respectively. However, the total P uptake was influenced only by ASW deficit levels in that the relatively minimum and maximum values were observed at 75% and 0% of ASW deficit levels, respectively. It can be concluded that the critical ASW deficit levels that affect yield and yield components of soybean and uptake of total P lie between 25% and 50% of available water deficit levels. The parameters started to decline significantly from the 50% of ASW deficit onwards. As it is a green house experiment, further study on more number of ASW deficit levels and soil types under different field conditions needs to be done to reach at a conclusive recommendation.

Coupling Effect of Water and Fertilizer on Soybean Yield and Nutrient Absorption

Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertilizer application,and vice versa;pods per plant,seeds per pod.and 100-seed weight had positive correlations with soybean yield,but the degrees of correlations of different treatments were various;LAI and dry matter accumulation could be significantly increased when watered and applied fertilizer with different levels,but high fertilizer application treatment didn't obtain the highest yield;watering could increase the absolute absorption amount of N,P,K in seeds,but the accumulation rates were various.

Effects of UV-B Radiation and Water Stress on Soybean Yield

Soybean Dongnong 47 was subjected to the experiments of increasing UV-B radiation and water stress on soybean yield components in different growth periods. The results showed that 100-seed weight greatly increased during the early stage of pod filling in the treatment of weak UV-B radiation, seed number per plant as well as seed weight per plant and Dongnong47 yield also increased, while the yield and yield components of Dongnong47 during the blossom to mature period were negatively affected in the treatment of intensive UV-B radiation. 100-seed weight of Dongnong47 all increased in the double factor treatments of UV-B radiation and water stress, with the drought intensified, seed number per plant, seed weight per plant and yield of Dongnong47 decreased, the change of 100-seed weight were various and the antagonistic action of UV-B radiation and water stress were related with their intensity.

Interaction of Carbon Dioxide Enrichment and Soil Moisture on Photosynthesis, Transpiration, and Water Use Efficiency of Soybean

Soybean (Glycine max (L.) Merrill) is one of the most important oil and protein sources in the world. Interactive effect of elevated carbon dioxide (CO2) and soil water availability potentially impact future food security of the world under climate change. A rhizotron growth chamber experiment was conducted to study soil moisture interactions with elevated CO2 on gaseous exchange parameters of soybean under two CO2 concentrations (380 and 800 μmol·mol-1) with three soil moisture levels. Elevated CO2 decreased photosynthetic rate (11.1% and 10.8%), stomatal conductance (40.5% and 36.0%), intercellular CO2 concentration (16.68% and 12.28%), relative intercellular CO2 concentration (17.4% and 11.2%), and transpiration rate (43.6% and 39%) at 42 and 47 DAP. This down-regulation of photosynthesis was probably caused by low leaf nitrogen content and decrease in uptake of nutrients due to decrease in stomatal conductance and transpiration rate. Water use efficiency (WUE) increased under elevated CO2 because increase in total dry weight of plant was greater than that of water use under high CO2 conditions. Plants under normal and high soil moisture levels had significantly higher photosynthetic rate (7% to 16%) favored by optimum soil moisture content and high specific water content of soybean plants. Total dry matter production was significantly high when plants grown under elevated CO2 with normal (74.3% to 137.3%) soil moisture level. Photosynthetic rate was significantly and positively correlated with leaf conductance and intercellular CO2 concentration but WUE was significantly negatively correlated with leaf conductance, intercellular CO2 concentration and transpiration rate. However, the effect of high CO2 on plants depends on availability of nutrients and soil moisture for positive feedback from CO2 enrichment.

Responses in gas exchange and water status between drought-tolerant and-susceptible soybean genotypes with ABA application

The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance(g_s), leaf water potential(ψ_w), and relative water content of leaves(%RWC) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype(C12) responded more rapidly than a drought-susceptible genotype(C08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWC and ψwin the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.

Water Footprint of Soybean, Maize and Wheat in Pergamino, Argentina

Nowadays more than 70% of the fresh water available worldwide is used for agriculture. In Argentina, extensive crops are not usually irrigated, so the cropping production depends mostly on rainfall water. In order to know how many liters of water are needed to produce a ton of soybeans, wheat and maize in the Pergamino district, Province of Buenos Aires, its Water Footprint was estimated by the Hoekstra method. Evaporation and rainfall data was obtained from SIGA INTA platform and production data was obtained from the Ministry of Agriculture. The results indicated that the average annual total water footprint values for soybean, corn and wheat crops for the period 2013-2018 in the Pergamino district, province of Buenos Aires, are 1,388 l∙kg−1, 693 l∙kg−1 and 1,249 l∙kg−1 respectively. These were lower than the global average reference values. The obtained results allowed future analysis advancing in the knowledge of the use of water productivity in grain production.

富钼专用保水剂对东北典型土壤保墒性能及大豆幼苗生长的影响

在东北集约化种植体系中,苗期水肥供应强度直接影响作物生长状况,并最终导致产量变异。富钼大豆专用保水剂是基于高分子材料合成与钼肥技术的耦合。针对东北2种典型土壤类型开展温室盆栽试验,通过二因子五水平的试验设计,研究土壤类型、保水剂类型及施用量对大豆苗期土壤水分利用效率及幼苗生长的影响。结果表明:1)施用不同剂量普通保水剂(H 2020)和富钼专用保水剂(GH 2021)均可在不同程度上提高土壤保水性能,并促进苗期大豆生长及地上部植株干质量;2)土壤含水率和大豆幼苗株高均随用量的增大而增加,且用量为0.5%的GH 2021显著促进大豆幼苗的生长,在黑土和风沙土条件下增幅分别可达68.0%和44.9%;3)0.5%剂量的GH 2021使风沙土土壤含水率提高343.1%,相较于施用H 2020保水性能提升33.6%;4)与H 2020相比,施用量为0.5%的GH 2021使风沙土条件下苗期大豆株高和地上部干质量分别提高16.3%和34.0%。综上,富钼专用保水剂在东北大豆种植区最佳应用范围为:2种土壤条件下,保水剂理论田间推荐用量为0.5%,其对风沙土的保墒性能优于黑土。该保水剂可用于提升干旱区土壤保水性能,改善苗期大豆生长环境和营养状况,最大限度激发东北大豆的增产潜力。

Novel Gluten-Free Amaranth and Oat Flour Cookies Fortified with Soybean Hulls

Soybean hulls, an abundant byproduct of soybean processing, contain rich phytochemicals, fibers, proteins, and minerals. Currently soybean hulls are primarily used as animal feeds. For value-added soybean hull utilization, 25% soybean hulls were substituted for amaranth or whole oat flour (WOF) in novel gluten-free cookies. Composition, nutritional values, water-holding capacities, correlation between properties, and pasting and rheological properties of soybean hulls, amaranth, and WOF were appraised in comparison to wheat flour. Water loss, cookie texture, and geometrical properties of the cookies were examined. The results disclosed that soybean hulls, amaranth and WOF contain higher protein content, minerals, fiber, special amino acids, and critical vitamins (C and K) than wheat flour. Considerably higher total amino acid content was found in soybean hulls (18.33%) than wheat flour (12.77%). Water-holding capacities increased by replacing amaranth and WOF with soybean hulls. Soybean hulls exhibited higher rheological elastic properties than amaranth, WOF and wheat flours. The soybean hulls utilized in amaranth or WOF cookies greatly improved their nutritional value, the water retention and moisture content along with acceptable physical properties when compared to wheat flour cookies. This study explored the feasibility and potential of utilizing soybean hulls with amaranth and WOF in gluten-free bakery products and other food applications.

Effect of pulse drip irrigation and mulching systems on yield, quality traits and irrigation water use efficiency of soybean under sandy soil conditions

Two field experiments were carried out during growing seasons 2010 and 2011, it executed in research farm of national research center in Nubaryia region, Egypt to study the effect of pulse drip irrigation and mulching systems for saving water, increasing and improving yield of soybean. The study factors were, pulse drip irrigation technology (adding of daily water requirements on 4 times, 8 times, 12 times compared with adding of daily water requirements on 1 time) and mulching systems (covering the soil with black plastic mulch “BPM”, rice straw mulch “RSM” and the control treatment was soil surface without mulch “WM”). The following parameters were studied to evaluate the effect of pulse drip irrigation and mulching systems: 1) Soil moisture distribution in root zone, 2) Growth characters of soybean plant, 3) Yield of soybean, 4) Irrigation water use efficiency of soybean “IWUE soybean”, and 5) Oil content and oil yield, 6) Protein content and protein yield, 7) Economical parameter. According to the economical view and the results of statistical analysis for effect of pulse drip irrigation and mulching systems on yield, quality traits and IWUE soybean indicated that, applying the irrigation requirements on 8 pulses/day with using BPM is the best conditions because under these conditions was occurred the highest value of yield, quality traits and IWUE soybean and there was significant deference between this case and other treatments. Where, pulse irrigation technique increase from water movement in horizontal direction than vertical direction hence improve from soil moisture distribution and wetted soil volume in root zone and using BPM decrease from evaporation process rate from soil surface hence decreasing of salts accumulation in addition to decreasing of weed growth in the root zone. All traits at AIR on 12 pulses/ day are decreased by increasing of pulses, this may be due to irrigation water was very small with every pulse at AIR on 12 pulses/day in addition increasing the total time of time-off, this mean, un-sufficient application for irrigation water to remove water stress in the root zone.

不同时期水分胁迫对御旱基因型大豆生理特性和产量的影响

为探讨御旱基因型大豆应答干旱胁迫生理和产量的响应机制,以御旱型辽豆14和干旱敏感型辽豆21为试验材料,分析不同生长阶段及抗性品种间的变化规律。2021和2022年连续两年分析水分胁迫对大豆株高、叶面积指数、叶绿素含量、器官生物量、器官含水量、根冠比等生理特性,产量及相关性状的影响。结果表明:随着生育进程的推进,各处理植株的株高、叶面积指数、各器官生物量逐渐累积,整体表现为:鼓粒期>结荚期>开花期>营养生长期。各个时期控水土壤干旱胁迫使植株的叶绿素含量、叶面积指数、株高、各器官含水量降低,但使植株的根冠比提高。相同水分条件下,叶绿素含量整体表现为辽豆21>辽豆14。植株各器官含水量表现为辽豆14>辽豆21。2021年结荚期和鼓粒期控水时,辽豆14的叶面积指数和株高高于辽豆21。同一时期控水,土壤水分提高使大豆根、茎、叶、叶柄、荚皮的干重提高,2020年结荚期和鼓粒期控水时,御旱基因型辽豆14的叶柄干重均显著高于干旱敏感型辽豆21。适宜土壤水分含量条件下两个品种的单株荚数、单株粒数和单株产量较高。各个时期控水,品种差异均显著影响大豆的单株荚数、单株粒数、百粒重和单株产量。同一时期相同水分条件下,大豆的单株荚数、单株粒数和单株产量表现为:辽豆14>辽豆21;而百粒重则表现为:辽豆21>辽豆14。本研究揭示了御旱基因型大豆应答干旱胁迫的生理特征,对指导我国大豆抗旱生产栽培具有重要的理论价值。

不同时期水分胁迫对大豆根系特性及产量的影响

为揭示抗旱基因型大豆根系应答干旱胁迫的响应机制,于2020年在辽宁省沈阳市开展盆栽试验,以抗旱基因型和干旱敏感型大豆为试材,探讨干旱(W1,土壤含水量为田间持水量的50%)、轻度干旱(W2,土壤含水量为田间持水量的60%)、适宜水分(W3,土壤含水量为田间持水量的80%)对大豆根系特性和产量的影响。结果表明:同一时期控水,W1和W2条件下,抗旱品种“辽豆14”的总根长和根表面积优于干旱敏感型品种“辽豆21”。一般情况下,平均根直径为0~0.5 mm的根长比例表现为:“辽豆21”>“辽豆14”,而平均根直径为0.5~1.0 mm的根长比例却表现为:“辽豆14”>“辽豆21”。随着生育进程的推进,大豆地上部鲜重、地上部干重、根干重逐渐累积,鼓粒期达最大值;一般情况下,同一控水时期,随着土壤含水量的增加,同一品种地上部鲜重、根鲜重、地上部干重、根干重值逐渐增加,但抗旱品种“辽豆14”的值一般优于干旱敏感型品种“辽豆21”。随着生育进程的推进,根冠比鲜重和根冠比干重值降低;土壤干旱提高了植株的根冠比。各个时期控水,品种和水分均显著影响了大豆的单株产量,干旱(W1)和轻度干旱(W2)均降低了2品种的单株产量,但抗旱品种“辽豆14”引起产量下降的值更低。干旱胁迫条件下,抗旱基因型大豆在总根长、根表面积、地上部干重、根干重、产量以及平均根直径为0.5~1.0 mm的根长比例方面,表现出优于干旱敏感型品种的优势。

转基因抗虫耐除草剂大豆JD321对根际土壤含水量和pH值的影响

为了评价转基因抗虫耐除草剂大豆JD321对土壤生态系统的影响,该实验研究了其对土壤主要理化性质的影响。在大豆苗期、花期、鼓粒期和成熟期,分析了转基因大豆JD321对根际土壤含水量和pH值的影响。与其对应的非转基因大豆相比,转基因大豆JD321的根际土壤含水量和pH值没有明显变化,除草剂处理转基因大豆也没有对土壤含水量和pH值产生明显影响,但土壤含水量和pH值在不同生育期间存在明显差异。研究结果为转基因大豆JD321的环境安全性提供了新的支撑。

乳清蛋白粉与豆乳不同质量比对凝固型沙棘酸奶品质的影响

以1 L鲜牛乳质量为基准,向其中加入乳清蛋白粉(WPP)、豆乳、沙棘果汁及菌种,混合发酵制备凝固型沙棘酸奶,探究WPP与豆乳不同质量比(WPP与豆乳总质量100 g,A组4∶0,B组3∶1,C组2∶2,D组1∶3,E组0∶4,F组不添加WPP和豆乳,G组不加沙棘果汁、WPP和豆乳)对凝固型沙棘酸奶理化特性、微观结构、质构特性及感官品质的影响。结果表明:B、C、D、E组酸奶发酵时间约为5 h,A、F、G组酸奶发酵时间约为6 h;各组酸奶脂肪含量差异不大,E组酸奶蛋白质含量最高,为4.55%;A组酸奶的持水力最高,为98.02%±0.05%;C组酸奶(硬度0.45 N±0.03 N,胶着性0.47 N±0.02 N,咀嚼性6.32±0.41,黏附性0.57 N·s±0.07 N·s)的质地和微观结构最佳,且C组在贮存3 d时的感官评分最高,为88.8。

中国大豆需水量时空演变趋势分析

[目的]探究中国大豆需水量的时空演变趋势。[方法]基于1971-2020年气象数据,采用作物系数法计算中国大豆需水量,采用Mann-KendaⅡ趋势检验与重标极差(R/S)分析中国大豆需水量及水分亏缺值的时空变化。[结果]中国大豆全生育期需水量、水分亏缺值分别为382、111 mm,总体上不缺水,但在北方干旱半干旱区、青藏高原区、黄土高原区的干旱缺水形势严重。在北方干旱半干旱区东部、东北平原区南部、黄淮海平原区西部、云贵高原区南部、华南区,大豆干旱缺水形势趋于恶化。未来在北方干旱半干旱区东部、云贵高原区西南部、青藏高原区西部等缺水地区,干旱大豆生育期内缺水形势呈恶化趋势,而在黄淮海地区西部、云贵高原区东南部、长江中下游地区南北部及华南区西部等丰水地区,大豆生育期内存在潜在的缺水危机。[结论]在东北平原区南部、黄淮海平原西部及长江中下游地区南北部等大豆扩种区域,未来大豆干旱形势呈加剧趋势,在这些地区扩大大豆种植面积时需采用节水措施以确保水资源可持续利用。

基于DRAINMOD的长江下游平原农田排水条件对大豆产量影响的模拟

为探讨改善农田排水条件对大豆产量的影响,结合大豆耐渍试验结果,考虑当前高标准农田建设要求,运用DRAINMOD田间水文模型模拟不同排水条件下农田降渍效果及大豆产量的变化规律。研究结果表明:DRAINMOD模型可准确预测研究区农田地下水位动态变化和作物产量;仅改善农田地表排水状况对农田降渍及提高大豆产量的作用有限,通过暗管排水提高地下排水强度,可有效降低农田渍害的发生率,保证大豆因渍害减产的几率低于10%;研究区大豆田除涝降渍的暗管排水系统最优布局为间距15~20m、埋深1.0~1.1m。研究成果可为研究区及类似地区高标准农田暗管排水系统建设及大豆高产稳产提供参考。

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。

不同浓度富氢水对大豆产量与品质的影响

【目的】探讨不同浓度富氢水(HRW)对大豆产量和品质的影响,为富氢水在大豆高产优质栽培中的应用提供理论依据。【方法】设不同浓度富氢水[0(CK)、30%HRW、60%HRW]处理,大豆幼苗长至株高约15 cm时,挑选长势一致的幼苗转移至室外进行盆栽试验,每周浇灌不同浓度富氢水(每盆1.5 L)至大豆成熟期,收获后分别对比不同处理的大豆植株表型和根瘤数量,并测定大豆生物量、单株荚数、单株籽粒数、百粒重、蛋白质和脂肪含量等产量和品质相关指标,评价不同浓度富氢水处理对大豆产量和品质的影响。【结果】与CK的生长指标比较,30%HRW处理的大豆地上部和根系干重均显著增加(P<0.05,下同),单株根瘤数显著减少;而60%HRW处理的大豆株高、单株根瘤数和根系干重与CK均无显著差异(P>0.05,下同)。与CK的大豆产量相关指标比较,30%HRW处理的单株荚数显著增加48.72%,单株荚重显著升高78.40%,单株粒数显著增加58.71%,百粒重增加18.92%;而60%HRW处理的单株荚数减少14.10%,单株荚重显著降低24.73%,单株粒数显著减少23.23%,百粒重降低22.44%。与CK的大豆品质相关指标比较,30%HRW处理的大豆蛋白质含量和脂肪含量差异不显著,而单株籽粒蛋白质总量显著增加84.94%,单株籽粒脂肪总量显著增加78.12%;60%HRW处理的蛋白质含量显著降低,而脂肪含量差异不显著,单株籽粒蛋白质总量显著降低56.37%,单株籽粒脂肪总量显著降低39.84%。【结论】30%HRW可改善大豆生长,显著增加大豆植株生物量积累,同时提高大豆籽粒产量和品质。

黄土塬区膜际玉米大豆间作对玉米光合特性、产量及水分利用效率的影响

为了筛选出黄土塬区膜际玉米、大豆最佳间作模式,采用膜侧3~5 cm精准精量播种的膜际栽培技术,于2022—2023年在陕西省神木市农技推广中心试验站开展试验,设置玉米单作(CJCJ)、大豆单作(SJSJ)以及玉米大豆间作2C2S(玉米和大豆行比2∶2)、2C4S(2∶4)、4C2S(4∶2)和4C4S(4∶4)6个处理,研究膜际玉米大豆间作对玉米光合特性、产量及水分利用效率的影响。结果表明,2022、2023年,玉米抽穗期各间作处理的净光合速率、气孔导度和蒸腾速率均高于CJCJ单作处理,其中,各处理间的气孔导度均存在显著差异。从2 a间玉米成熟期地上部干物质量来看,2C4S处理较其他处理增加3.27%~81.42%,该处理有利于间作玉米地上干物质量的积累。玉米大豆复合种植模式中,各处理的玉米产量以2C4S处理最高,2022、2023年群体产量分别达到8157.04、13506.62 kg/hm^(2),与CJCJ处理相比分别增加了37.08%、20.88%。2 a中,2C4S、4C2S处理的水分利用效率较CJCJ处理高出3.04%~12.19%。综上所述,各间作处理中玉米和大豆行比2∶4带型的复合种植模式为最优配比,可增加种植系统中玉米作物的总产量,适宜在陕北地区推广应用。

垄作和覆膜下盐碱地水盐运移和大豆产量的变化

选择河北省黄骅市中度盐碱土区布置夏播大豆[Glycine max(L.)Merr.]田间试验,共设平播(对照)、平播覆膜、垄作及垄作覆膜4个处理,研究垄作和覆膜对土壤水盐运移和大豆产量的影响。结果表明,与传统平播方式相比,平播覆膜处理对土壤水盐运移和大豆产量的影响不显著;垄作处理能显著改变土壤水盐分布,特别是大豆生长中后期降雨量开始减少后,垄作定植沟会产生叠加集雨效果,显著提高大豆生长中期0~20 cm和20~40 cm土壤含水量,减缓作物生长后期向表层返盐进程,有效降低土壤表层盐分含量,对保障大豆植株生长和产量均有一定的促进效果,可增产27.2%;垄作覆膜处理效果与垄作处理类似,覆膜措施影响不显著。垄作技术可以作为滨海盐碱地夏播大豆种植的农耕措施。