The segmentation of plant disease images enables researchers to quantify the proportion of disease spots on leaves, known as disease severity. Current deep learning methods predominantly focus on single diseases, simple lesions, or laboratory-controlled environments. In this study, we established and publicly released image datasets of field scenarios for three diseases: soybean bacterial blight (SBB), wheat stripe rust (WSR), and cedar apple rust (CAR). We developed Plant Disease Segmentation Networks (PDSNets) based on LinkNet with ResNet-18 as the encoder, including three versions: ×1.0, ×0.75, and ×0.5. The ×1.0 version incorporates a 4 × 4 embedding layer to enhance prediction speed, while versions ×0.75 and ×0.5 are lightweight variants with reduced channel numbers within the same architecture. Their parameter counts are 11.53 M, 6.50 M, and 2.90 M, respectively. PDSNetx0.5 achieved an overall F1 score of 91.96%, an Intersection over Union (IoU) of 85.85% for segmentation, and a coefficient of determination (R2) of 0.908 for severity estimation. On a local central processing unit (CPU), PDSNetx0.5 demonstrated a prediction speed of 34.18 images (640 × 640 pixels) per second, which is 2.66 times faster than LinkNet. Our work provides an efficient and automated approach for assessing plant disease severity in field scenarios.

为提高砂姜黑土土壤水分的估测精度,本研究以河南省西平县砂姜黑土为研究对象,通过配制不同含水率土壤样本并在室内进行高光谱测量,对土壤样本高光谱数据平滑(SR)、倒对数[LOG(1/R)]、一阶微分(FD)、多元散射校正(MSC)、去包络线(CR)光谱变换后,结合连续投影算法(SPA)识别最佳特征波段,采用偏最小二乘回归(PLSR)、支持向量机回归(SVR)的机器学习方法和堆叠(Stacking)集成学习方法分别构建土壤含水率反演模型.结果表明:经MSC变换后光谱中土壤含水率相关信息增强最多;SPA算法能对砂姜黑土含水率光谱数据进行降维和特征信息提取;经反射光谱MSC变换后由PLSR和SVR集成的Stacking集成模型决定系数最高(R2=0.963)、均方根误差最小(RMSE=1.7).研究表明,Stacking集成学习模型有效提升了模型的精度和泛化能力,是砂姜黑土含水率最佳反演模型.

鉴于测绘土地资源管理人才培训实践教学环节严重缺乏,教学反馈机制不科学,学生就业竞争力薄弱,根据河南理工大学土地资源管理专业实际情况,以专业竞赛为主要驱动因素,在资源平台、课程平台、综合能力平台三个层面,充分调动学生积极性,培养学生的实践能力、分析和解决问题的能力,从学科竞赛成绩、毕业生就业、研究生入学考试三方面系统研究培养模式改革的实际效果,为新工程背景下高校土管人才培养模式改革提供理论参考.

Background: The combination of biochar and organic manure has substantial local impacts on soil properties, greenhouse gas emissions, and crop yield. However, the research on soil health or quality is still in its early stages. Four pot experiments were carried out: C (30 g biochar (kg soil)−1), M (10 g manure (kg soil)−1), CM (15 g biochar (kg soil)−1 + 5 g manure (kg soil)−1), and the control (without any amendments). Results: When compared to C and M treatments, the MWD of CM was reduced by 5.5% and increased by 4.9%, respectively, and the micropore volume (5–30 m) was increased by 17.6% and 89.6%. The structural equation model shows that soil structural parameters and physical properties regulate the distribution of micropores (5–30 μm) in amended soil. Conclusion: Our studies discovered that biochar mixed with poultry manure had antagonistic and synergistic effects on soil aggregate stability and micropore volume in vertisol, respectively, and thus enhanced crop yield by 71.1%, which might be used as a technological model for farmers in China’s Huang-Huai-Hai region to improve low- and medium-yielding soil and maintain soil health.

为实现高标准农田土壤重金属Zn含量的快速测定,本文以西平县土壤Zn为研究对象,通过采集168个土壤样本进行室内实验,获得土壤高光谱数据(400～2400 nm)并进行Savitzky-Golay平滑后,利用5种光谱变换,结合连续投影算法识别最佳特征波段,采用偏最小二乘回归方法构建Zn元素最佳反演模型.结果表明:二阶微分(SD)在1409 nm波段的相关性(-0.502)最大,一阶微分(FD)在2323 nm波段的相关性(0.491)最大,去包络线(CR)在2439 nm波段的相关性(0.476)最大;倒数对数(LOG)、一阶微分、二阶微分、平滑曲线(SG)、去包络线的拟合度(R2)在0.65～0.70之间,相对分析误差(RPD)处于1.71～2.29之间,其中去包络线的拟合度(R2=0.70、RPD=2.29)最高.经过5种光谱变换后的光谱反射率可有效突出光谱反射率的变化特征,并用于构建反演模型;土壤重金属Zn的最佳模型是以去包络线光谱变换为最佳偏最小二乘模型.

为定量反演丹江口水库水质指标含量,明晰水质指标的时空分布特征、迁移转化规律,以南水北调中线工程水源地丹江口水库为研究对象,根据哨兵2号卫星(Sentinel-2)遥感影像不同波段组合的反射率,结合2016年2月的采样点总氮(TN)与氨氮(NH3-N)水质监测数据建立BP神经网络模型,反演2016—2020年TN与NH3-N含量,以此分析库区TN与NH3-N含量的时空变化特征,并探析其变化的影响因素.结果表明:构建的BP神经网络模型中TN和NH3-N的拟合精度均较高,R2分别为0.863和0.877,适用于丹江口水库TN和NH3-N遥感反演研究.2016—2020年丹江口水库水质整体呈向好趋势,NH3-N含量保持Ⅰ类水质标准,而TN含量在Ⅲ类与Ⅳ类水质标准之间.研究表明,利用Sentinel-2影像波段所建立的BP神经网络模型,适用于TN与NH3-N含量的遥感反演,以此分析不同季节适合的反演模型,可以为大型湖泊水生态环境改善及水质监管提供技术支撑.

土壤颜色是反映土壤发生、分类及肥力特征的一项重要物理指标.黑色土壤一般有较高的有机质含量,但砂姜黑土是低有机质含量的黑色土壤典型代表.以黄淮海平原3种典型砂姜黑土为研究对象,分别采用添加六偏磷酸钠分散剂后振荡并结合多层次超声处理(HP)、添加碳酸钠分散剂后振荡并结合多层次超声处理(SC)和仅超声波处理(US)等3种方法分散土壤,然后依次提取土壤浅色组分(颗粒态有机质(POM)、白(W)、 浅白(LW))和黑色组分(浅黑(LB)、 黑(B)、深黑(DB)),旨在建立土壤黑色物质的有效提取方法.结果表明,HP方法提取黑色物质(LB、B和DB)的量最多,且提取量与土壤黑度间相关性最显著(P<0.01),是提取砂姜黑土黑色物质的最佳方法.不同提取组分中的土壤黑度与有机质含量无明显相关性,砂姜黑土的显色主要取决于由蒙皂石吸附有机质形成的黑色纳米有机-无机复合体,受有机质含量的直接影响相对较小.本研究提出了一种砂姜黑土黑色物质提取方法,并初步明确了黑色物质组成特征,可为揭示砂姜黑土有机质形成与累积机制提供参考.

The Calci-Aquic Vertisols comprise one of the largest areas with low crop yields in China normally characterized with black color, high smectite contents but low organic matter contents. This study aims to establish a physical method for extracting black matter from the Calci-Aquic Vertisols, and explore the formation mechanism of black nano-organo-mineral complexes of the soils. The alternation of freezing-thawing and adding dispersant followed by oscillation and multi-level ultrasound(HOMU) method were proposed and tested to disperse soil and extract black matters from the topsoil layers (0-40 cm) and black soil layers (40-70 cm) of three Calci-Aquic Vertisols. Six different components including POM, white, light white, light black, black and nano-black were extracted successively and analyzed for blackness, organic matter content, particle gradation, mineral composition and elemental oxides. The nano-organo-mineral complexes are found be responsible for the Calci-Aquic Vertisols appearing black. Smectite (SM) absorbing organic matters mainly through cation bridges of Fe3+ and Al3+, hydrogen bond, van der Waals force formed the black nano-organo-mineral complexes which consists the main parts of the black matters in the Calci-Aquic Vertisols. Agricultural activities increased the organic matter contents in the topsoil layers, but the difference of formation environment resulted in the poorer crystallinity and higher content smectites and thus higher nano-organo-mineral complex contents and blackness in the black soil layers in the Calci-Aquic Vertisols. The result in this research is of great value for understanding the organic matter turnover and improving the productivity of the Calci-Aquic Vertisols.

Soil organic matter (SOM) and interparticle forces, including the electrostatic repulsive force (ERF), surface hydration repulsive force (SHRF) and van der Waals attractive force (vDWAF), play crucial roles in aggregate stability. However, few studies investigated their coupled effects on aggregate stability in variably charged soils, in which soil particle interactions are more complex than in permanently charged soils due to the coexistence of positive and negative charges and the variable surface charge characteristics. Therefore, this study aims to: 1) investigate the combined effects of soil solution pH and the overlapping of electric double layers (EDLs) between positively charged Fe/Al (hydro)oxides and negatively charged SOM on the ERF and aggregate stability before (control) and after SOM removal and after straw incubation for 240 days; and 2) evaluate the importance of soil interparticle forces and SOM for aggregate stability in a permanently charged temperate soil (Vertisol) and a variably charged subtropical soil (Ultisol). Soil aggregate stability was determined by measuring the release of small particles (w(< d)%) after aggregate breakdown at different KCl concentrations (10(-1) to 10(-5) mol L-1). Soil solution pH was adjusted by varying KCl concentration. In both soils, the w(< d)% increased exponentially with the net force of the soil interparticle forces. However, in contrast to the Vertisol, the w(<d)% of the differently treated Ultisol showed almost no change before the KCl concentration decreased to 10(-2) mol L-1 and continuous changes after the KCl concentration decreased to 10(-2) MOl L-1. In addition, the differences in the w (< d)% between the SOM removal treatment and the control and straw incubation treatments were much larger in the Ultisol than in the Vertisol. In the Ultisol, the ERF did exhibit little and continuous increase over the whole range of tested pH. When considering the impact of the overlapping of oppositely charged EDLs between Fe/Al (hydro)oxides and SOM, a much stronger reduction in ERF was observed in the control and straw incubation treatments and at lower KCl concentrations. Consequently, in both the Vertisol and Ultisol, aggregate stability is essentially controlled by the soil interparticle forces, whereas the effects of soil solution pH and the overlapping of oppositely charged EDLs between SOM and Fe/Al (hydro)oxides on the ERF must be considered in variably charged soils (i.e. Ultisol). Moreover, SOM can play a more important role in aggregate stability in subtropical soil than in temperate soil.

Soil color is an important physical property for studying the genesis, formation environment and fertility of the soil. Generally, the soil with a higher organic matter content appears darker, but the soil color of the Calci-Aquic (CA) Vertisols with low organic matter contents also appear very black. The results based on the traditional chemical extraction method of black matters indicated that the combination of highly aromatized humus with soil particles makes the CA Vertisols appearing black. However, the chemical extraction method only partially extracted the humus ingredients, and what is more important, it destroyed the structure of organic matter and organic-inorganic complexes. The study on the black matter extracted from the CA Vertisols by the physical extraction method without destroying structures of organic-inorganic complexes showed that the black organic-inorganic complexes formed from smectites adsorbing organic matters were the decisive factor of the CA Vertisols apprearing black. However, the effects of the structures of the organic matters absorbed by the smectites on the color of the black organic-inorganic complexes remains unclear. Therefore, this study aims to explore the mechanism of these organic-inorganic complexes appearing black from the structural characteristics of the organic matters in the black organic-inorganic complexes and their relationships to smectites. Firstly, the physical method was adopted to extract the light-colored components (>53 mu m particles, white (W) and light white (LW))) and black components (light black (LB), black (B) and nano black (NB)) from the topsoil layer (0 similar to 40 cm) of the typical CA Vertisols in three sites of the Huang-Huai-Hai Plain in China. The blackness, organic matter structures and smectite contents of the extracted components were then measured by Spectrophotometer, solid-state C-13 NMR spectrometer and X-ray diffractometer. Finally, correlation analysis and path analysis of smectites, organic matter structures and soil blackness showed that the direct and indirect effects through alkyl C, carboxyl C, amino C and O-alkyl C on soil blackness are strong in all three soils, while both of the direct and indirect effects of aromatic C content and aromaticity on soil blackness are weak. Besides, the direct and the indirect effects through carboxyl C, amino C and alkyl C of smectites on soil blackness are also strong. Therefore, it is the carboxyl C, amino C, alkyl C and O-alkyl C, rather than the aromatic carbon and high aromaticity in the traditional view, that determine the black color of the CA Vertisols were by being selectively absorbed by the widely existing smectites in the CA Vertisols to form organic-inorganic complexes.

不同复垦年限下土壤孔隙微结构特征及其与复垦年限的关系尚未明确.为了探明矿区不同复垦年限土壤孔隙的微结构特征,选取河南省辉县市赵固煤矿复垦3 a(FK3)和10 a(FK10)土壤处理,并以原状地貌(CK)为对照.利用显微CT技术扫描200 mm田间原状土柱,结合Image J软件及其插件对土壤孔隙结构进行三维重建及分析.结果表明,复垦土壤孔隙结构稳定具有空间和时间的层次性和顺序性.随着复垦年限的增加,土壤孔隙度、孔隙数量、成圆率、分形维数和欧拉值总体呈逐渐增加趋势.从土壤剖面来看,0 ～ 30 mm土壤孔隙结构尚处于紊乱状态,孔隙数量表现为FK3＞CK＞FK10,而40～80 mm土层趋于稳定,孔隙数量呈现为CK＞FK3＞FK10.土壤剖面孔隙度与孔隙数量变化趋势基本一致.与FK3相比,CK和FK10的分形维数分别显著(P＜0.05)增加了16.1％和12.3％,但FK10与CK间无显著差异(P＜0.05).相关分析表明,分形维数能综合表征土壤孔隙数量和形态特征,可作为沉陷区复垦土壤结构恢复状况的定量评价指标.本研究表明,复垦年限对沉陷区土壤结构修复具有较大影响,土壤结构达到稳定状态需经过10 a左右的时间.

为探明中部粮食主产区不同土地利用方式对农田土壤活性有机碳(LOC)、碳库管理指数(CMI)和作物产量的影响,选取河南省新郑市耕地(T1)、葡萄园地(T2)、枣树园地(T3)、蔬菜地(T4)为研究对象,对比分析了4种典型土地利用方式下的土壤活性有机碳和碳库管理指数的变化规律.结果表明,0~100 cm土层不同土地利用方式的总有机碳(TOC)存在明显差异,整体表现为随土层深度增加而降低.其中,0~20 cm土层不同土地利用方式下TOC质量分数差异较大,T4、T3、T2较T1分别高60.0%、53.3%和13.3%;LOC和CMI较未利用土地(T0)均明显提高.作物产量与速效氮、碳库活度(L)显著正相关(P<0.05),但与LOC和CMI无显著相关关系,可能是作物产量的统计口径不同所致.不同土地利用方式对土壤TOC、LOC和CMI的影响存在较大差异,LOC和CMI可以作为不同土地利用方式和土壤碳库质量的评价指标.

运用SPSS软件(简单相关分析法、主成分分析法、回归分析法)、AMOS软件(结构方程模型),分析砂姜黑土主要理化性状对土壤肥力的直接和间接影响.结果表明:砂姜黑土结构性、透气性差,肥力低,具有一定的保肥能力和强烈的干缩湿胀特性;不同区域的砂姜黑土理化性状差别较大;4种统计方法对砂姜黑土主要理化性状分析得到的4种结果有异同,全磷、全氮是土壤肥力的主要影响因子,pH和总孔容对于土壤肥力的影响最小,不同之处在于土壤有机质与线膨胀系数的相关关系上.总体来说,砂姜黑土主要理化性状会对土壤肥力有直接和间接的作用,直接作用影响更大.

施肥方式是改善砂姜黑土大孔隙结构的重要措施之一.本研究选取中国科学院与河南省人民政府合作的“砂姜黑土改良”长期施肥定位试验平台(河南省西平县)的3个处理:CK(对照,秸秆还田)、SC(常规施用化肥)和SM处(施有机肥),运用显微CT扫描田间原状土柱,采用ImageJ 1.51K软件及其插件对土壤孔隙结构进行三维重建,定量研究了不同施肥方式下土壤孔隙数量、形态和空间变化特征.结果表明:砂姜黑土孔隙度和土壤孔隙数量变化趋势一致.土壤总孔隙度变化顺序为SM＞ CK＞ SC.其中,SM处理不同土层孔隙数量最多,空间变异也最大;CK处理次之,SC处理居最后.SM和CK处理的分形维数最高,土壤孔隙结构复杂且稳定,SC处理分形维数较低,孔隙结构相对简单.SM处理综合表现较优,是砂姜黑土结构改良的一种推荐施肥方式.

Carbon sequestration rate in cropland soil is an important index to evaluate the effect and potential capacity of soil carbon sequestration. Accurate estimation of soil organic carbon sequestration rate is very important for studying cropland soil fertility and environmental effect. In this research, a typical fluvor-aquic soil area, Fengqiu County of Henan Province, located in Yellow Ri-ver basin of Huang-Huai-Hai Plain of China, was chosen as the study area. A total of 70 soil samples were collected according to combined unit grid method of soil utilization with soil type in 2011. The soil organic carbon content, soil mechanical composition, soil bulk density and pH were mea-sured, respectively. The spatial variability of the soil organic carbon sequestration rate of Fengqiu County in recent 30 years was also investigated by using geostatistics method and geography information system (GIS) technique, based on the comparative analysis of soil organic carbon content from samples surveyed in 2011 and the results surveyed by the 2nd state soil survey of China in 1981. In addition, the influencing factors of the soil carbon sequestration rate were quantitatively analyzed by statistical methods, such as significance testing, regression analysis and variance analysis. The results revealed that the soil organic carbon sequestration rate of recent 30 years was about 0.33 t C·hm-2·a-1 with a coefficient variance of 74%, which belonged to a medium variation. The spatial variability characteristics of soil organic carbon sequestration rate was of sheet distribution, which was higher in the west and lower in the east, and decreased from the central region to the south and north. The primary influencing factors of soil organic carbon sequestration rate were structural factors, such as soil type, mechanical composition, soil bulk density and pH, which could explain 59.5% of the spatial variability in the study area. The secondary factors were random factors, such as straw application and fertilizing amount, which could explain 40.5% of the spatial variability.

Withpoor physical properties and low organic matter content, lime concretion black soil is one of the lowest productive soils and is widely distributed in the Huang-Huai-Hai Plain in China. Although the physical and chemical properties of lime concretion black soil influenced by exogenous organic matter have been widely reported, few studies have focused on the effects of synchronous application of organic materials with different stabilities in lime concretion black soil. Thus a two-year pot experiment was conducted at the State Experimental Station of Agro-Ecosystem in Fengqiu to evaluate the effects of organic materials with different stabilities (biochar, organic fertilizer and straw) on the physico-chemical properties of lime concretion black soil and maize yield. Eight treatments were designed based on applications of different organic materials with the same inputs of carbon and nitrogen, which were CK (no fertilizer), straw (S), organic manure (M), biochar (C), 1/2 straw + 1/2 organic manure (SM), 1/2 biochar + 1/2 straw (CS), 1/2 biochar + 1/2 organic manure (CM), and 1/3 biochar + 1/3 organic fertilizer + 1/3 straw (CSM). Compared with CK, the application of different organic materials decreased soil bulk density by 19.60%-32.23% and increased saturated soil moisture, field capacity and total porosity by 7.91%-28.99%, 10.47%-30.76% and 10.36%-28.21%, respectively. There were significant differences in total organic matter and labile organic matter contents of soil between CK and organic materials application treatments. The trends of increase in different components of organic matter were similar. On the other hand, the variation range of high labile organic matter was obviously greater than that of total organic matter. The high labile organic matter content increased by 39.22%-8.83%, whereas that of total organic matter increased by 11.00%-37.00% under organic materials treatments. Bulk density of CSM (1.28 g.cm-1) was lower than those of C (1.30 g.cm-1) and S (1.36 g.cm-1). Total porosity of CSM was highest (58.53%) among all treatments. Total porosity under CS, SM, S, C and M treatments was 56.90%, 54.38%, 55.62%, 53.18% and 50.38%, respectively. Total organic matter content of CS, CM, CSM, C and S was 30.76 g.kg-1, 32.99 g.kg-1, 31.45 g.kg-1, 25.36 g.kg-1 and 26.16 g.kg-1, respectively. Maize yield for different treatments were similar in trend to that of total organic matter content. Grain yield for CS, SM and CSM was respectively 463.67 g.pot-1, 376.31 g.pot-1 and 471.77 g.pot-1; higher than that of C, S and M. Overall, mixed application of biochar, straw and organic fertilizer was by far better than the application of sole organic material in terms of improving soil physico-chemical properties and maize yield.

Soil enzyme activities, as an important biological indicator of soil fertility, can quickly reflect the change of soil properties. In order to improve the fertility of fluvo-auic soil, we assessed the effects of long-term fertilization on Soil enzyme activities. Based on two long-term fertilization experiments located in Zhengzhou and Fengqiu, the activities of urease, alkaline phospahtase, catalase, protease and invertase under different fertilization treatments in plough layer soil (0~15 cm) were investigated, as well as the correlations between soil enzyme activities and soil chemical properties were analyzed. The results showed that: (1) Although both of topsoil types at two field experiments were fluvo-auic soil, the effects of different fertilization on soil enzyme activities were very different. Soil catalase activities was not significant influenced by long-term fertilization in Zhengzhou, whereas NK fertilization increased the soil catalase activities by 58.3% compared with control in Fengqiu. (2) Without the application of phosphate fertilizer, protease activity increased by 119% compared with the control when the ratio of nitrogen and potassium was 1∶1; however, protease activity descended by 20% when the ratio was 2∶1. (3) Different fertilization was helpful for the urease enzyme activity, and the highest urease enzyme activity was found in organic compost treated soil, which increased by 41.1% and 106.4% in Zhengzhou and Fengqiu, respectively. (4) Long-term fertilization did not significantly increase the soil alkaline phosphatase activity, nevertheless the straw incorporated treatment dominantly induce the activity of alkaline phosphatase by the percent of 133.5% in comparison with that in the CK plots; (5) Invertase activity of all fertilization treated soil was improved in Zhengzhou, and the increase ranged 95.5% in the NK plots to 439% in straw incorporated fertilizer plots. In Fengqiu, compared to the control, NK,OM fertilization improved the invertase activity, 81.3%, 180% respectively. And (6) there was a positive correlation among urease activity, alkaline phosphatase activity and invertase activity, and urease activity and invertase activity positively related to soil organic matter and total N, respectivly. The result suggested that compost and straw application made the soil enzyme activity remain at a high level and contributed to improvement of soil fertility compared with mineral fertilization treatment, and the ratio of N/K exerted an significant influence on soil enzyme activity.

以河南省新郑市为研究区,分别采用三维克里格(Kriging)插值法和三维反距离加权(IDW)插值法模拟不同深度土壤有机质和全氮含量的三维空间分布特征,并采用交叉验证法,比较2种三维空间插值方法的预测精度.研究表明,有机质和全氮沿不同土层深度(0 ～20 em、20～40 em、40 ～ 60 cm)均表现出明显的空间分布差异,3种深度土壤有机质含量的平均值变化范围为11.31 ～15.48g/kg,全氮的变化范围为0.48 ～0.79g/kg,均随土层加深而降低;土壤有机质和全氮的三维空间分布表达的信息量更加丰富,可直观展示任意土体切面的养分含量分布信息;通过三维克里格方法得到的有机质插值结果的预测精度高于反距离加权法,全氮亦然,三维克里格插值法更能真实反映土壤养分的三维空间分布特征.

The quick assessment approaches for accurately measuring water-use efficiency (WUE) in maize under water stress are important to water-saving agriculture. We investigated how and whether carbon isotope composition (δ 13C) and specific leaf area (SLA) could be used to assess WUE for maize as influenced by water stress. A pot experiment was conducted twice during six typical maize (Zea mays) growth stages of seedling, jointing, booting, tasseling, filling and maturity, respectively. The ratio between the activities of ribulose 1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase decreased bundle sheath leakiness (φ) under water deficiency, caused more 13C to be assimilated, and resulted in increased δ 13C in leaves. Water stress increased the fractionation of 13C when assimilates were transported from leaf to stem, indicating that water stress affected leaf expansion and translocation of assimilates from leaf to stem, and resulted in thicker leaves and lower SLA. WUE showed significant positive correlations with leaf δ 13C and SLA, implying that leaf δ 13C and SLA could effectively reflect the drought adaptation and high WUE under different water conditions.

The invention discloses a kind of straw-returning method, first collect straw, dry, pulverize, then the straw after pulverizing is put into immersion in treatment fluid；After being filtered to remove soak, by straw steaming and decocting；Finally the straw after steaming and decocting is buried into field ditch, apply fertilizer, suppression of soil.The present invention is first by crushed stalk, again through treatment fluid immersion, steaming and decocting, then in fertilizer, add composite synergist (sodium onitrophenol, poly-aspartate, Radix potentillae anserinae, gibberellins, hydroxyl acetamide, sodium tripolyphosphate), in conjunction with the microorganism in soil, make lignin energy contained by straw degradable, substantially increase Straw decomposing efficiency, not only shorten the straw-returning time, also reduce the generation of wheat root disease when maize straw.