Saponin synthesis and cotton growth is antagonistically regulated by solar UV-B radiation

Background: Earlier we have reported that the exclusion of solar UV-B increased the growth and yield of cotton plants as compared with ambient UV-B. The UV-B radiation effects on the saponins and the impact of ambient and reduced UV-B on the accumulation of saponins has not been investigated yet. Thus a field experiment was conducted to study the influence of solar UV-B on the growth response and saponin synthesis in cotton(Gossypium hirsutum) var. Vikram plants by the exclusion of UV-B. The cotton plants were grown in specially designed iron chambers, wrapped with filters that excluded UV-B(<315 nm), or transmitted ambient UV-B.Results: Exclusion of ambient UV-B enhanced the growth of cotton plants in terms of plant height and leaf area.Greater plant height in UV-B excluded plants was due to elongated internode and more number of nodes.Enhancement in growth was accompanied by a decrease in the accumulation of saponins, which was quantified by the spectrophotometric, TLC and HPLC methods. Solvent extraction of saponins from the internodes and leaves were used for the bioassay of Amaranthus hypocotyl growth and expansion of cucumber cotyledons. Extracts obtained from the UV-B excluded plants(leaves and internodes) promoted the growth to a larger extent as compared with the extracts obtained from ambient grown plants.Conclusions: The result indicates that solar UV-B may possibly suppress the plant growth by regulating the synthesis of natural growth inhibitor's like saponin.

Recognition of cotton growth period for precise spraying based on convolution neural network

Dynamic acquisition of crop morphology is beneficial to real-time variable decision of precise spraying operations in fields.However,the existing spraying quantity regulation has high tolerance on the statistical characteristics of regional morphology,so expensive LiDAR and ultrasonic radar can’t make full use of their high accuracy,and can reduce decision speed because of too much detail of branches and leaves.Therefore,designing a novel recognition system embedded machine learning with low-cost monocular vision is more feasible,especially in China,where the agricultural implements are medium sizes and cost-sensitive.In addition,we found that the growth period of crops is an important reference index for guiding spraying.So,taking cotton as a case study,a cotton morphology acquisition by a single camera is established,and a cotton growth period recognition algorithm based on Convolution Neural Network(CNN)is proposed in this paper.Through the optimization process based on confusion matrix and recognition efficiency,an optimized CNN model structure is determined from 9 different model structures,and its reliability was verified by changing training sets and test sets many times based on the idea of kfold test.The accuracy,precision,recall,F1-score and recognition speed of this CNN model are 93.27%,95.39%,94.31%,94.76%and 71.46 ms per image,respectively.In addition,compared with the performance of VGG16 and AlexNet,the convolution neural network model proposed in this paper has better performance.Finally,in order to verify the reliability of the designed recognition system and the feasibility of the spray decision-making algorithm based on CNN,spraying deposition experiments were carried out with 3 different growthperiods of cotton.The experiments’results validate that after the optimal spray parameters were applied at different growth periods respectively,the average optimum index in 3 growth periods was 42.29%,which was increased up to 62.24%than the operations without distinguishing growth periods.

Effects of NaCl stress on the biochemical substances in Bt cotton as well as on the growth and development and adult oviposition selectivity of Helicoverpa armigera

Background:Recently,due to the development of food security strategies,cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China.Under the condition,to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils,it is important to study the larval growth and development of H.armigero and to study adult oviposition selectivity in H.armigera adults that feed on NaCI-stNaCled cotton plants.Results:In this study,Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H.armigera.The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol-L-1,75 mmol-L-1 and 150 mmol-L-1,respectively.The results showed that the expression of Bt protein was significantly inhibited for NaCI-stressed Bt cotNaClThe content of soluble protein and K+ in the leaves of cotton were decreased,while the content of gossypol and Na+were increased.In addition,the 5th instar H.armigera larvae exhibited shorten the life span in a 13-day trial period.Under enclosure treatments and at different female densities,the adult oviposition of H.armigera decreased on high NaCI-stressed nontransgenic coNaCl,while the oviposition on Bt cotton tended to first increase but then decrease under low,moderate and high NaCl stress treatments.Conclusions:Under certain content ranges of NaCl stress treatments,larval of H.armigera growth and development,and adult oviposition were no significant difference in the change for a certain period.However,under high NaCl stress,larval growth,development and adult oviposition were affected,which may provide insights for the prevention and control of H.armigero for Bt cotton in saline-alkali soils.

Growth, Physiological and Molecular Responses of Cotton (Gossypium arboreum L.) under NaCl Stress

Salinity is one of the most serious growth limiting factor, therefore, no longer being ignored. Although, cotton is fairly salt tolerant;its sensitivity at crop stand and yield is affected. This study is planned to identify the growth, physiological and molecular parameters in local cotton varieties FDH 171 and FDH 786 under NaCl stress. There was 100% seed germination but hypocotyl length was reduced at increasing level of NaCl. Plant height, fresh and dry biomass were reduced as the plants were subjected to increased stress of NaCl. Stomatal conductance, transpiration and photosynthetic rate and ionic imbalance were found to be reduced under the gradual increase in NaCl stress and affected the plant’s overall physiological processes. PCR product of AtNHX3 has been identified in stressed and non-stressed plants. Thus, the genotypes FDH 171 & FDH 786 were found tolerant to adoption of salt stress and could be used as a source in crop improvement.

Evaluation of Impact of Pollen Grains from Bt,Bt/CpTITransgenic Cotton and Bt Corn Plants on the Growth andDevelopment of the Mulberry Silkworm,Bombyx moriLinnaeus (Lepidoptera:Bombycidae)

The S-endotoxin genes of Bacillus thuringiensis (Bt) and proteinase inhibitor (PI) genes are two kinds of genes popularly used for developing transgenic plants resistant to insect pests. To clarify whether there is any risk concerning the effects of pollens from these transgenic crops on non-target insects with economic importance, such as the effects on the growth and development as well as cocoon quality of the silkworm, Bombyx mori Linnaeus, a series of feeding experiments were conducted, using pollens from transgenic cotton or corn containing cry 1Ac, cry1A+CpTI or crylAb genes, compared with pollens from non-transgenic normal cotton and corn as well as the non-pollen treatment. In contrast to the latter ones, pollens from transgenic plants showed no significant adverse effects on larval mortality, cocoon weight, pupa weight, cocoon shell weight, pupation rate, emergence rate and fecundity of the silkworm after neonates were fed with the pollens for 72 h. In addition, no dosage effects of pollens were found. Though the duration of 1st instar larvae was prolonged in the case of feeding with transgenic pollens as compared with those of the non-pollen treatment , but they were not significantly different from those fed with pollens from non-transgenic cotton or corn. Meanwhile, the body weight of the 3rd instar molters fed with transgenic pollens was obviously different from those for non-pollen treatment, and was all significantly heavier than that of the controls. Consequently, it is considered that the adverse effect of pollens from transgenic insect-resistant cotton and corn on the growth and development of the silkworm is negligible.

不同矿化度水源膜下滴灌对棉花土壤盐分分布及生长的影响

利用微咸水膜下灌溉是缓解干旱区农业灌溉资源短缺的有效途径之一,分析不同矿化度水源膜下滴灌对土壤盐分分布及作物生长的影响对于确定灌溉水源矿化度阈值具有重要意义。开展4 a不同梯度矿化度水源膜下滴灌棉花测坑试验,设置6个处理矿化度分别为1 g/L(CK)、2 g/L(A)、3 g/L(B)、4 g/L(C)、5 g/L(D)和6 g/L(E),分析不同梯度矿化度水源膜下滴灌土壤盐分累积及棉花生长特征,确定微咸水膜下滴灌棉花灌溉矿化度阈值。结果表明:2019-2022年,0~100 cm平均土壤电导率以每年0.920 dS/m、0.995 dS/m、1.196 dS/m和1.188 dS/m的速率呈线性增长的趋势。随着灌溉年限增加,不同梯度微咸水膜下滴灌下土壤电导率呈现增加趋势。5 g/L和6 g/L处理土壤盐分累积最大,分别为38.70%和39.19%;灌水12 h后,宽行表层20~40 cm土壤盐分累积最为明显,土壤电导率为0.30~2.1 dS/m;窄行土壤盐分在40~60 cm土层处出现累积,土壤电导率为1.26~1.93 dS/m。矿化度为3 g/L水源膜下滴灌棉花土壤盐分累积量较小,对棉花叶片光合作用指数影响最小,生长指标和产量达到最大,微咸水膜下滴灌棉花适宜的灌溉水源阈值为3 g/L。

应用Cotton2k模型模拟北疆棉花生长结果的分析

Cotton2k模拟模型是一个动态模型,能在生理过程水平上模拟棉花的生长发育和产量形成.通过应用棉花生产管理系统（GOSSYM/COMAY）中一种机理性很强的棉花生长模拟模型Cotton2k,对新疆北部地区棉花的生长状况进行模拟.从生育期的模拟结果分析得出除60%吐絮期误差较大外,其他生育期的模拟结果非常好;从形态发育模拟和实测结果比较表明：形态发育在花铃期前基本吻合;各器官干物质重的模拟和实测结果比较表明：除叶重误差较大外,其他的模拟结果较为满意,特别是植株干重的模拟可以作为精准农业水肥诊断的依据;植株中氮浓度的模拟误差较大,其原因分析有二：（1）棉花在生长发育过程中本身的生物学特性决定了每个生育期对不同肥的吸收量值不同,导致模拟值与观测值有差异;（2）在播种前应对试验地的肥力进行测定,使原始含N量的差异排除,会对模拟结果的精度有所提高.各层土壤含水量的模拟结果表明：耕作层0～45的土壤水分含量差异较大,但是45 cm以下土层的土壤含水量模拟结果与实测值基本吻合;不同水肥处理方式下的产量模拟结果和实测结果比较,产量模拟的误差较大.

COTTON2K在新疆棉花精准种植管理中的应用

简述了棉花模拟模型COTTON2K的新增特点,并利用新疆2002～2003年棉花数据对该模型进行校正和验证,指出模型验证中存在的问题.

噻苯隆复配植物生长延缓剂对棉花生长发育和产量的影响

为探究叶面喷施噻苯隆复配不同植物生长延缓剂对棉花生长发育和产量的调控效应,于2022年7—10月在新疆沙雅县海楼镇团结村进行大田试验,新陆中84号为供试棉花品种,以0.1%噻苯隆为主,分别复配缩节胺(W1)、调环酸钙(W2)、烯效唑(W3)、氟节胺(W4),以清水为CK,采用随机区组试验设计,在棉花化学打顶前后各喷施一次,分析其对棉花农艺性状、干物质积累与分配、叶面积指数、SPAD值和产量的影响。结果表明,各处理中W3处理各项调查指标总体最优。具体表现如下:吐絮期,W3处理棉花株高、株宽、第3果枝长、第7果枝长、叶枝长较CK分别降低1.23%、3.14%、10.96%、11.72%、18.92%;施药后30 d,SPAD值和蕾铃的干物质积累量较CK分别增加2.05%和9.98%,生殖器官干物质占比较CK提升7.61%,叶面积指数较CK提高10.85%;单株铃数较CK增加11.28%,籽棉产量较CK增加11.23%。综上,在化学打顶前后各喷施一次0.1%噻苯隆450 mL/hm^(2)+5%烯效唑75 g/hm^(2)能够抑制棉花无限生长,提高棉花叶面积指数和叶片SPAD值,促进棉株生殖生长,提高单株铃数,从而显著提高棉花产量。

不同种植模式和品种对棉花光合物质生产及产量的影响

【目的】研究不同种植模式与品种对棉花光合物质生产及产量的影响。【方法】试验于2022年在新疆阿克苏地区沙雅县海楼镇进行,选择2种不同株型结构的棉花品种源棉11号、新陆中80号、新陆中84号和J206-5,选用2种种植模式:76 cm等行距(1膜3行)和(66+10)cm宽窄行(1膜6行),设置田间试验分析不同种植模式及品种对棉花生育进程、植株形态、叶面积指数、净光合速率、干物质积累和产量的影响。【结果】不同棉花品种在1膜3行处理下较1膜6行处理生育期缩短4~6 d,株高、始果枝高度、果枝夹角和平均果枝长度受种植模式影响较大。盛铃前期之前,不同株型棉花品种在1膜3行处理下的叶面积指数较高。但随着生育期推移,株型松散型的源棉11号、J206-5和株型紧凑的新陆中80号、新陆中84号分别在1膜3行处理、1膜6行处理下叶面积指数下降幅度较小,在棉花生育后期能维持较高的叶面积指数。盛花期前,不同株型棉花品种的净光合速率均表现为1膜3行处理高于1膜6行处理,但在盛花期至吐絮阶段,株型松散型的源棉11号、J206-5和株型紧凑的新陆中80号、新陆中84号净光合速率分别在1膜3行处理、1膜6行处理下达到最大值且下降缓慢,延长了光合作用持续时间,有利于棉花后期产量形成。株型松散型的源棉11号、J206-5在1膜3行处理下较1膜6行处理皮棉产量增加15.45%~17.23%,株型紧凑的新陆中80号、新陆中84号在1膜6行处理下皮棉产量较1膜3行处理增产9.23%~12.00%。【结论】不同株型棉花品种应选择适宜的种植模式,才能进一步发挥其增产潜力。株型松散的棉花品种适宜在76 cm等行距下种植,株型紧凑的棉花品种适宜在(66+10)cm模式下种植。

Promoting the production of salinized cotton field by optimizing water and nitrogen use efficiency under drip irrigation

Cotton is the main economically important crop in Xinjiang,China,but soil salinization and shortage of water and nutrients have restricted its production.A field experiment was carried out in the salinity-affected arid area of Northwest China from 2018 to 2019 to explore the effects of nitrogen and water regulation on physiological growth,yield,water and nitrogen use efficiencies,and economic benefit of cotton.The salinity levels were 7.7(SL)and 12.5 dS/m(SM).Drip irrigation was used with low,medium and adequate irrigation levels representing 60%,80%and 100%of cotton crop water demand,respectively,and three nitrogen applications,i.e.,206,275 and 343 kg/hm^(2),accounting for 75%,100%and 125%of local N application,respectively were used.The multi-objective optimization based on spatial analysis showed that,at SL salinity,water use efficiency(WUE),nitrogen use efficiency(NUE),economic benefit and yield simultaneously reached more than 85%of their maxima at 379.18-398.32 mm irrigation and 256.69-308.87 kg/hm^(2).At SM salinity,WUE,yield and economic benefit simultaneously reached more than 85%of their maxima when irrigation was 351.24-376.30 mm and nitrogen application was 230.18-289.89 kg/hm^(2).NUE,yield and economic benefit simultaneously reached their maxima at 428.01-337.72 mm irrigation,and nitrogen application range was 222.14-293.93 kg/hm^(2).The plants at SL salinity had 21.58%-46.59%higher WUE rates,14.91%-34.35%higher NUE rates and 20.71%-35.34%higher yields than those at SM salinity.The results are of great importance for the nutrient and water management in cotton field in the arid saline area.

生物炭施加对微咸水滴灌棉田土壤水热盐及棉花生长的影响

为解决北疆淡水缺乏和土壤质量下降的问题,通过大田试验探明不同灌水矿化度及生物炭施加量对棉田土壤水热盐环境及棉花生长的影响。设置4个生物炭施加水平(B0:0 t·hm^(-2)、B1:20 t·hm^(-2)、B2:40 t·hm^(-2)、B3:60 t·hm^(-2))和3个灌水矿化度水平(S1:1 g·L^(-1)、S2:3 g·L^(-1)、S3:5 g·L^(-1)),采用双因素完全随机组合试验,研究不同处理对土壤水盐温分布、棉花生长指标、干物质积累量、产量及水分利用率的影响。结果表明:施加生物炭与灌水矿化度的增加均使得土壤含水率和含盐量升高。生物炭施加量的增加使得平均土壤温度升高,升高幅度介于5.9%~15.1%,灌水矿化度对平均土壤温度存在显著影响,但各处理间差异不显著。生物炭施加提高棉花株高、叶面积指数和地上部干物质量。棉花籽棉产量和水分利用率最大值均出现在B2S2处理,为6526.4 kg·hm^(-2)和2.01 kg·hm^(-2);最小值均出现在B0S3处理,较B2S2处理分别减少18.50%和26.87%。构建多元回归方程,基于棉花高产、高水分利用率;结合归一化处理和空间分析得出最佳生物炭施加量、灌水矿化度区间分别为26~46 t·hm^(-2)和2.45~3.04 g·L^(-1)。

棉花黄萎病生防菌筛选鉴定及根瘤菌DG3-1对棉花生长的影响

本研究旨在发掘南疆棉花内生菌种质资源来防治棉花黄萎病,探究根瘤菌对棉花生长的影响。采用常规组织分离法分离棉花不同组织内生细菌;平板对峙法筛选拮抗棉花黄萎病菌的内生菌,并对其进行分子鉴定;通过盆栽试验研究根瘤菌对棉花生长的影响。结果显示,棉花不同组织内生细菌的数量具有一定差异,根部最多,其次是叶和茎;在分离获得的31株内生菌中,有11株对棉花黄萎病菌具有拮抗活性,抑菌率在35.99%~68.28%之间,经鉴定,9株为芽孢杆菌,2株为根瘤菌,其中,根瘤菌DG3-1对棉花黄萎病菌的抑制率为(56.63±1.82)%;盆栽试验结果表明,菌株DG3-1处理后棉株的地上鲜重、地上干重、地下鲜重、地下干重、叶绿素含量分别比对照增加2.12、2.09、1.05、0.75、1.75倍。菌株DG3-1对棉花黄萎病菌有较好的抑制作用,并且对棉花的生长有一定的促生作用,是防治棉花黄萎病的潜力菌株,可为微生物菌剂的研发提供菌种资源。

不同种植模式下氮肥基追比对棉花生长发育及产量的影响

研究棉花适宜的种植模式和氮肥基追比,为新疆棉花高产高效发展提供技术支撑。以棉花品种新陆中84号为材料,于2022年在新疆阿克苏地区沙雅县海楼镇进行田间试验。试验采用裂区试验设计,主因素为种植模式:一膜6行[(66+10)cm宽窄行、株距12 cm,M6]和一膜3行(76 cm等行距、株距6 cm,M3);副因素为氮肥基追比:0∶10(N0)、2∶8(N2)、4∶6(N4)。共6个处理,各处理总施氮量均为纯氮320 kg/hm^(2),在棉花的整个生育期对生育进程、农艺性状、叶面积指数(LAI)、净光合速率(Pn)、干物质量、产量及产量构成进行调查和测定。结果表明,M3种植模式各氮肥基追比处理平均皮棉产量较M6种植模式增加22.0%,2种模式分别以M3N4处理和M6N2处理皮棉产量最高,为3251.90 kg/hm^(2)和2895.42 kg/hm^(2),其中盛蕾期、盛花期、盛铃期M3N4处理Pn较M6N2处理分别增加41.2%、12.1%、34.0%。M3种植模式各氮肥基追比处理吐絮期平均干物质积累量较M6种植模式增加35.1%,平均单株铃数、单铃质量、籽棉产量较M6种植模式分别增加20.6%、5.3%、21.7%。随氮肥基追比增加,棉花生育期延长,吐絮期M6种植模式下N0处理分别比N2、N4处理提前5、8 d,M3种植模式下N0处理比N2、N4处理提前4、6 d;2个种植模式下不同氮肥基追比处理LAI均表现为N4>N2>N0;M6种植模式下N2处理棉花盛花期Pn、吐絮期地上部干物质量、单株铃数、单铃质量、籽棉产量分别较N0和N4处理提高9.2%和8.9%、18.2%和42.5%、19.8%和18.3%、9.3%和5.5%、30.3%和25.4%,M3种植模式下N4处理棉花盛花期Pn、吐絮期地上部干物质量、单株铃数、籽棉产量分别较N0和N2处理提高21.1%和6.7%、32.9%和24.0%、11.3%和12.3%、12.5%和11.4%,单铃质量差异不显著。综合考虑种植模式和氮肥基追比对棉花产量的协同提高效应,在设置试验条件下,选择76 cm等行距种植模式,氮肥基追比控制在4∶6时较为适宜。

水氮互作对南疆膜下滴灌棉花生长及水氮利用效率的影响

水肥是影响作物生产力水平的重要物质基础,探索水氮互作对南疆膜下滴灌棉花生长、籽棉产量以及水氮利用效率的影响。试验设计4个施氮水平(底肥+追肥:0+0、84+225 kg/hm~2、84+300 kg/hm~2、84+375 kg/hm~2),分别记为N1、N2、N3、N4;每个施氮水平设计3个依据潜在作物需水量与降雨量差值(W=ETc-P)确定的不同灌水水平(0.8 W、1.0 W、1.2 W,分别记为W1、W2、W3)。结果显示,土壤中硝态氮主要分布于0~40 cm土层,随灌水量的增大而降低,随施氮量的增大而增大。株高、茎粗、干物质重则随着灌水量的增加而增加,随着氮肥用量的增加,表现为先增大后减小的趋势。株高、茎粗、地上干物质量的最大值均出现在W3N3处理,分别为85.97 cm、11.86 mm、94.37 g。籽棉产量随灌水量的增加而增加,与W1处理相比,W2和W3的平均籽棉产量分别提高了15.54%和1.33%。二元二次回归分析得出,当施氮量为342.67~410.0 kg/hm~2,灌水量为381.7~445.9 mm(0.92~1.07 W)。可以使南疆膜下滴灌棉花的产量、水分利用效率、氮肥农学利用效率的综合效益最大化。研究成果可为南疆膜下滴灌棉花的水氮优化管理提供理论依据和技术支撑。

不同植物蛋白源替代鱼粉对青鱼生长及免疫的影响

该试验聚焦青鱼的饲料创新方法,通过应用不同植物蛋白源替代鱼粉对青鱼生长性能、全鱼和肌肉化学成分组成、肠道及肝胰脏酶活的影响。将豆粕SBM、菜粕RSM、棉粕CSM、花生粕PM分别替代试验饲料中10%的鱼粉FM(CP,67%),配制成5组等氮等能的试验饲料,分别记为FM、SBM、RSM、CSM、PM。以鱼粉、豆粕、菜粕、棉粕、花生粕为主要蛋白源按相同成分含量配制成粗蛋白(39.34%)、粗脂肪(6.81%)的青鱼配合饲料,并以此为对照组进行试验。研究结果表明,豆粕相较于其他植物蛋白源更适合加入饲料,用豆粕替代试验饲料中<10%的鱼粉较为理想。

棉副产品型发酵全混合日粮对卡拉库尔羊生长性能、营养物质表观消化率及瘤胃发酵参数的影响

本试验旨在探究饲喂棉副产品型发酵全混合日粮对卡拉库尔羊生长性能、营养物质表观消化率及瘤胃发酵参数的影响。选取36只健康、2~3月龄、体重[(26.0±2.2)kg]相近的卡拉库尔羊公羔,随机分为3组,每组12只,每只羊作为1个重复。CK组饲喂100%棉副产品型全混合日粮,FFG组饲喂50%棉副产品型发酵全混合日粮+50%棉副产品型全混合日粮,EFG组饲喂80%棉副产品型发酵全混合日粮+20%棉副产品型全混合日粮。预试期15 d,正试期60 d,测定生长性能、营养物质表观消化率和瘤胃发酵参数。结果显示:1)饲喂50%或80%的棉副产品型发酵全混合日粮均能显著或极显著提高卡拉库尔羊的平均日增重(ADG)和干物质采食量(DMI)(P<0.05或P<0.01),且EFG组的DMI极显著高于FFG组(P<0.01)。2)饲喂80%的棉副产品型发酵全混合日粮能显著或极显著提高粗蛋白质(CP)和中性洗涤纤维(NDF)表观消化率(P<0.05或P<0.01)。3)饲喂80%的棉副产品型发酵全混合日粮能显著降低瘤胃液pH并显著提高乙酸浓度(P<0.05),饲喂50%或80%的棉副产品型发酵全混合日粮均能显著提高瘤胃液氨态氮和丙酸浓度(P<0.05)。综上所述,饲喂80%的棉副产品型发酵全混合日粮可以提高卡拉库尔羊的生长性能、CP和NDF表观消化率,促进瘤胃发酵。

不同矿化度水源膜下滴灌棉田土壤水盐动态和作物生长模拟

为构建适用于干旱区膜下滴灌条件的土壤水盐动态分布和棉花生长模型,基于2020—2021年的田间试验,经过对SWAP模型的土壤、土壤水力功能和作物生长等模块进行率定和验证,对灌溉水矿化度为1、2、3、4、5、6 g·L^(-1)时的土壤水盐分布特征、作物生长过程和干物质累积分配进行数值模拟。结果表明:(1)土壤含水率与土壤含盐量的模拟精度以20~100 cm土层较好,0~20 cm土层模拟精度较差,其中土壤含水量的模拟效果优于土壤含盐量;随着灌溉水源矿化度的增加,土壤含水率和含盐量的模拟误差逐渐变小。(2)不同矿化度水源膜下滴灌棉花叶面积指数模拟效果较好(R2=90.72%,RMSE=0.35 cm^(2)·cm^(-2),NRMSE=8.73%,IOA=0.98)。(3)不同矿化度水源膜下滴灌棉花茎干物质累积量模拟效果较好(R2=89.08%,RMSE=6.12 g,NRMSE=23.16%,IOA=0.96)。研究结果表明,SWAP模型可以较好地对不同矿化度水源膜下滴灌的土壤水盐动态分布和棉花生长过程进行模拟。

加气渗灌模式下灌水定额与棉秆还田深度对棉花生长及产量的影响

为了探究加气渗灌模式下灌水定额和棉秆还田深度对棉花生长和产量的影响,本文以新陆中88号为研究对象,探究灌水定额和棉秆还田深度对棉花株高、茎粗、干物质量以及叶绿素相对含量的调控效应。结果表明,棉花受灌水定额影响较大,植株株高、茎粗、干物质量和叶片叶绿素相对含量均随着灌水定额的增大呈增加趋势。总体来看,在同一灌水定额条件下,25 cm土层处理的叶绿素相对含量大于15 cm和35 cm处理;棉秆还田深度为25 cm时,棉花株高、茎粗以及单株棉花籽棉产量均为最佳。

不同施氮量对棉花鲁棉338生长发育及产量的影响

为明确不同施氮量对棉花生长发育及产量的影响,以鲁棉338为试验材料,采用单因素随机区组试验设计,设置5个施氮水平,研究不同施氮水平对鲁棉338株高、叶片SPAD值和产量的影响。结果表明:随着棉花生育进程的推进,不同施氮水平下的株高均呈现逐渐上升的趋势;施氮处理棉花功能叶片SPAD值显著高于不施氮处理;施氮量300、400 kg/hm^(2)的处理棉花单株铃数、单铃重、籽棉产量、皮棉产量较高。综合来看,在鲁棉338种植生产中,施氮量控制在300 kg/hm^(2)最为适宜。