Xin Xu, Shuaijie Shen, F. Gao, Jian Wang, Xinming Ma, Shuping Xiong, Zehua Fan
. The study was carried out in order to clarify the effects of different water and irrigation conditions on crop models and remote sensing assimilation results. It involved taking winter wheat from 17 test sites in Henan Province as the research object and calibrating the World Food Studies model. The ensemble Kalman filter algorithm was used to calibrate the two modes and Moderate-resolution Imaging Spectroradiometer-Leaf Area Index of the calibrated world food studies model. The study found that the average error of the world food studies model for simulating flowering and maturity periods is within 2 days, the R 2 of the leaf area index calibration results is between 0.87-0.98, and the R 2 and root mean square error of the verification results are 0.77 and 1.06 respectively. Under the latent model, the R 2 of the world food studies model taking account of the water supply situation and the assimilation results without taking account of the water supply situation are 0.50 and 0.48, respectively. In the water restriction mode, the R 2 increased from 0.79 to 0.86 compared with the assimilation results where the water supply was not considered. The results show that: depending on the water supply of different regions, selecting the corresponding assimilation parameters can effectively improve the prediction accuracy of crop models and remote sensing assimilation for wheat yields under different water and irrigation conditions.
{"title":"Considering different water supplies can improve the accuracyof the WOFOST crop model and remote sensing assimilation in predicting wheat yield","authors":"Xin Xu, Shuaijie Shen, F. Gao, Jian Wang, Xinming Ma, Shuping Xiong, Zehua Fan","doi":"10.31545/intagr/154892","DOIUrl":"https://doi.org/10.31545/intagr/154892","url":null,"abstract":". The study was carried out in order to clarify the effects of different water and irrigation conditions on crop models and remote sensing assimilation results. It involved taking winter wheat from 17 test sites in Henan Province as the research object and calibrating the World Food Studies model. The ensemble Kalman filter algorithm was used to calibrate the two modes and Moderate-resolution Imaging Spectroradiometer-Leaf Area Index of the calibrated world food studies model. The study found that the average error of the world food studies model for simulating flowering and maturity periods is within 2 days, the R 2 of the leaf area index calibration results is between 0.87-0.98, and the R 2 and root mean square error of the verification results are 0.77 and 1.06 respectively. Under the latent model, the R 2 of the world food studies model taking account of the water supply situation and the assimilation results without taking account of the water supply situation are 0.50 and 0.48, respectively. In the water restriction mode, the R 2 increased from 0.79 to 0.86 compared with the assimilation results where the water supply was not considered. The results show that: depending on the water supply of different regions, selecting the corresponding assimilation parameters can effectively improve the prediction accuracy of crop models and remote sensing assimilation for wheat yields under different water and irrigation conditions.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47749550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ravi Gangwar, M. Makádi, B. Bresilla, Mohammed Zain, T. Weldmichael, I. Demeter, A. Táncsics, M. Cserhati, T. Szegi
. This study was conducted in order to understand the effects of land use and soil types on microbial activity and community structure. Soil samples were collected from four different soil types (Solonetz, Solonchak, Chernozem and Gleysol) being used under different land use practices (arable, pasture and meadow). The soil chemical properties, moisture content, microbiological activity and community size were investigated. The principal component analysis results showed that differ - ent land uses and soil types are clearly separated based on the chemical properties of the soil. The canonical correspondence analysis results revealed that more than 78% of variation in the microbiological properties of the samples could be explained by environmental factors. Significant biological differences were observed among the different land use practices and soil types, and also soil cultivation affected the different groups of soil microbes. Sampling sites were separated into two main clusters (Bray-Curtis) based on certain microbiological properties, salt-affected and non-salt-affected soils. The soil types were the main driving factor, with high soil taxonomic distances, however, low taxonomic distances indicated that land use had more pronounced effects on soil microbiological properties.
{"title":"Effects of land uses and soil types on microbial activity and community structure","authors":"Ravi Gangwar, M. Makádi, B. Bresilla, Mohammed Zain, T. Weldmichael, I. Demeter, A. Táncsics, M. Cserhati, T. Szegi","doi":"10.31545/intagr/155096","DOIUrl":"https://doi.org/10.31545/intagr/155096","url":null,"abstract":". This study was conducted in order to understand the effects of land use and soil types on microbial activity and community structure. Soil samples were collected from four different soil types (Solonetz, Solonchak, Chernozem and Gleysol) being used under different land use practices (arable, pasture and meadow). The soil chemical properties, moisture content, microbiological activity and community size were investigated. The principal component analysis results showed that differ - ent land uses and soil types are clearly separated based on the chemical properties of the soil. The canonical correspondence analysis results revealed that more than 78% of variation in the microbiological properties of the samples could be explained by environmental factors. Significant biological differences were observed among the different land use practices and soil types, and also soil cultivation affected the different groups of soil microbes. Sampling sites were separated into two main clusters (Bray-Curtis) based on certain microbiological properties, salt-affected and non-salt-affected soils. The soil types were the main driving factor, with high soil taxonomic distances, however, low taxonomic distances indicated that land use had more pronounced effects on soil microbiological properties.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44835898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bo Li, Ying Luo, Changchun Guo, Yonggang Yang, Xiaojuan Yuan, Mengwen Xing, P. Fan, Chuanhai Shu, Feijie Li, Haojun Fu, Zhiyuan Yang, Zongkui Chen, Jun Ma, Yuanyuan Sun, Yongjian Sun
. This study aimed to evaluate the relationship between the physicochemical properties and lodging index of different stem internodes and the yield of direct-seeded rice. Two treatments of wheat straw returning (returning and non-returning) and five potassium application rates of 0, 62.5, 125, 187.5, and 250 kg ha -1 were applied. Wheat straw returning combined with a potassium application rate of 125 kg ha -1 significantly promoted potassium accumulation, increased total soluble sugar and lignin contents, improved breaking moment, reduced the flattening rate and lodging resistance index of different internode stems, and increased the yield. Correlation analysis revealed that compared with those of the 4th and 5th internodes, potassium content and accumulation and total soluble sugar and lignin contents of the 3rd internode were significantly positively correlated with yield (r = 0.85**-0.93**) and negatively correlated with the stem flat rate and lodging index (r = -0.67*– -0.79**), which improved lodging resistance in collaboration with the 4th and 5th internodes (r = 0.82**-0.95**). Increasing potassium accumulation, total soluble sugar and lignin content, and reducing stem flatness of the 3rd stem internodes are important factors for improving lodging resistance of direct-seeded rice and may provide a basis for improving the 4th and 5th stem internodes.
本研究旨在评价不同茎节的理化性质和倒伏指数与直播水稻产量之间的关系。采用秸秆还田和不还田两种处理，施钾量分别为0、62.5、125、187.5和250 kg ha-1。秸秆还田与125 kg ha-1的施钾量相结合，显著促进了钾的积累，增加了总可溶性糖和木质素含量，改善了破碎时刻，降低了不同节间茎的压扁率和抗倒伏指数，提高了产量。相关分析表明，与第4和第5节间相比，第3节间的钾含量、积累量、总可溶性糖和木质素含量与产量呈显著正相关（r=0.85**-0.93**），与茎扁平率和倒伏指数呈负相关（r=-0.67*-0.79**），与第4和第5茎节协同提高了倒伏抗性（r=0.82**-0.95**）。增加钾积累、总可溶性糖和木质素含量以及降低第3茎节的茎平坦度是提高直播水稻倒伏抗性的重要因素，可为提高第4和5茎节提供依据。
{"title":"Effects of wheat straw returning and potassium application rates on the physicochemical properties and lodging resistance of different stem internodes in direct-seeded rice","authors":"Bo Li, Ying Luo, Changchun Guo, Yonggang Yang, Xiaojuan Yuan, Mengwen Xing, P. Fan, Chuanhai Shu, Feijie Li, Haojun Fu, Zhiyuan Yang, Zongkui Chen, Jun Ma, Yuanyuan Sun, Yongjian Sun","doi":"10.31545/intagr/155271","DOIUrl":"https://doi.org/10.31545/intagr/155271","url":null,"abstract":". This study aimed to evaluate the relationship between the physicochemical properties and lodging index of different stem internodes and the yield of direct-seeded rice. Two treatments of wheat straw returning (returning and non-returning) and five potassium application rates of 0, 62.5, 125, 187.5, and 250 kg ha -1 were applied. Wheat straw returning combined with a potassium application rate of 125 kg ha -1 significantly promoted potassium accumulation, increased total soluble sugar and lignin contents, improved breaking moment, reduced the flattening rate and lodging resistance index of different internode stems, and increased the yield. Correlation analysis revealed that compared with those of the 4th and 5th internodes, potassium content and accumulation and total soluble sugar and lignin contents of the 3rd internode were significantly positively correlated with yield (r = 0.85**-0.93**) and negatively correlated with the stem flat rate and lodging index (r = -0.67*– -0.79**), which improved lodging resistance in collaboration with the 4th and 5th internodes (r = 0.82**-0.95**). Increasing potassium accumulation, total soluble sugar and lignin content, and reducing stem flatness of the 3rd stem internodes are important factors for improving lodging resistance of direct-seeded rice and may provide a basis for improving the 4th and 5th stem internodes.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43367506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. No tillage was introduced to Northeast China to prevent the soil degradation caused by conventional tillage systems. However, there are concerns that no tillage will result in soil mechanical impedance. In this study, we investigated the effects of conventional tillage and no tillage on soil strength properties using a long-term field study initiated in 2011 on a silt clay loam soil. In 2018 and 2019, soil bulk density, water content, the degree of compactness, and penetrometer resistance were measured before tillage and after planting, and also, the changes in soil profile water content and penetrometer resistance were monitored during drying periods. Results showed that conventional tillage led to the formation of a compacted zone beneath the cultivated layer, with higher bulk density, degree of compactness, and penetrometer resistance values. After converting from conventional tillage to no tillage for 8 to 9 years, the bulk density, penetrometer resistance, and degree of compactness were increased to a moderate extent in the topsoil but were lowered in the subsurface soil. During drying periods, as compared to conventional tillage plots, the no tillage plots maintained higher water contents, which resulted in lower penetrometer resistances below a 15 cm depth and the later arrival of the threshold penetrometer resistance of 2 MPa. Long-term no tillage alleviated subsoil compaction and retarded drought-induced soil strength development.
{"title":"Long-term no tillage alleviates subsoil compaction and drought-induced mechanical impedance","authors":"Hengfei Wang, Li Wang, T. Ren","doi":"10.31545/intagr/154596","DOIUrl":"https://doi.org/10.31545/intagr/154596","url":null,"abstract":". No tillage was introduced to Northeast China to prevent the soil degradation caused by conventional tillage systems. However, there are concerns that no tillage will result in soil mechanical impedance. In this study, we investigated the effects of conventional tillage and no tillage on soil strength properties using a long-term field study initiated in 2011 on a silt clay loam soil. In 2018 and 2019, soil bulk density, water content, the degree of compactness, and penetrometer resistance were measured before tillage and after planting, and also, the changes in soil profile water content and penetrometer resistance were monitored during drying periods. Results showed that conventional tillage led to the formation of a compacted zone beneath the cultivated layer, with higher bulk density, degree of compactness, and penetrometer resistance values. After converting from conventional tillage to no tillage for 8 to 9 years, the bulk density, penetrometer resistance, and degree of compactness were increased to a moderate extent in the topsoil but were lowered in the subsurface soil. During drying periods, as compared to conventional tillage plots, the no tillage plots maintained higher water contents, which resulted in lower penetrometer resistances below a 15 cm depth and the later arrival of the threshold penetrometer resistance of 2 MPa. Long-term no tillage alleviated subsoil compaction and retarded drought-induced soil strength development.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46921595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. Hoppers are frequently used in steel silos, especially in farm facilities and food industries. These structures occasionally have an oblique hopper with an eccentric outlet to improve the flow of material during discharge. The 2006 version of the European standard EN 1991-4 uses classical Walker theory to predict wall pressures on concentric hoppers, but oblique hoppers are not considered. The authors have developed a Finite Element Model to predict the wall pressures on oblique hoppers and several sensitivity analyses have been made to study the possible influence of different parameters including outlet eccentricity, the outlet cir cumferential position, the aspect ratio of the silo and hopper, and different stored materials. The results show that the circumferential location and eccentricity of the outlet are the main factors affect ing the pressures on oblique hoppers. A semi-empirical equation is proposed to estimate the expected pressures on oblique hoppers which is designed to match with the maximum normal pressure obtained from the simulation, and to provide a good representation for the circumferential distribution of normal pressures. The results of this research may be of interest with regard to the upcoming revised version of the European standard EN 1991-4.
{"title":"A semi-empirical equation to predict filling wall pressures on oblique conical hoppers","authors":"E. Gallego, J. Fuentes, F. Ayuga","doi":"10.31545/intagr/152675","DOIUrl":"https://doi.org/10.31545/intagr/152675","url":null,"abstract":". Hoppers are frequently used in steel silos, especially in farm facilities and food industries. These structures occasionally have an oblique hopper with an eccentric outlet to improve the flow of material during discharge. The 2006 version of the European standard EN 1991-4 uses classical Walker theory to predict wall pressures on concentric hoppers, but oblique hoppers are not considered. The authors have developed a Finite Element Model to predict the wall pressures on oblique hoppers and several sensitivity analyses have been made to study the possible influence of different parameters including outlet eccentricity, the outlet cir cumferential position, the aspect ratio of the silo and hopper, and different stored materials. The results show that the circumferential location and eccentricity of the outlet are the main factors affect ing the pressures on oblique hoppers. A semi-empirical equation is proposed to estimate the expected pressures on oblique hoppers which is designed to match with the maximum normal pressure obtained from the simulation, and to provide a good representation for the circumferential distribution of normal pressures. The results of this research may be of interest with regard to the upcoming revised version of the European standard EN 1991-4.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43441207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. The study aimed to determine the effect of randomly applied soil-improving cropping systems on the variability of soil thermal conductivity, heat capacity, and thermal diffusivity over the course of a 3-year (2016-2018) study. The field experiment included the control and the following soil-improving cropping systems: liming, leguminous catch crops for green manure, farm yard manure, and liming+leguminous catch crops+farmyard manure together with spring oats (2017) and spring wheat (2018). The parameters such as bulk density, water content, and values of soil thermal conductivity, heat capacity, and thermal diffusivity have been determined. The thermal properties were measured at the current water content in situ and in water-saturated and dry soil states in the laboratory. The thermal properties in the wet year of 2017 increased in the subareas with a predominance of leguminous catch crops for green manure, farmyard manure, and liming+leguminous catch crops+farmyard manure, whereas the soil-improving cropping systems effect was not consistent after stubble tilling in the dry year of 2018. Cross-semivariograms which used the sand content as an auxiliary variable and cokriging produced a better prediction than the semivariograms and kriging. The fractal analysis indicated that the number of subareas differing in thermal properties was mainly modified by water content and bulk density. The spatial spread of the soil thermal properties during the water-saturated and dry states increased in subareas with a higher bulk density.
{"title":"Spatial variability of thermal properties in relation to the application of selected soil-improving cropping systems (SICS) on sandy soil","authors":"B. Usowicz, J. Lipiec","doi":"10.31545/intagr/152122","DOIUrl":"https://doi.org/10.31545/intagr/152122","url":null,"abstract":". The study aimed to determine the effect of randomly applied soil-improving cropping systems on the variability of soil thermal conductivity, heat capacity, and thermal diffusivity over the course of a 3-year (2016-2018) study. The field experiment included the control and the following soil-improving cropping systems: liming, leguminous catch crops for green manure, farm yard manure, and liming+leguminous catch crops+farmyard manure together with spring oats (2017) and spring wheat (2018). The parameters such as bulk density, water content, and values of soil thermal conductivity, heat capacity, and thermal diffusivity have been determined. The thermal properties were measured at the current water content in situ and in water-saturated and dry soil states in the laboratory. The thermal properties in the wet year of 2017 increased in the subareas with a predominance of leguminous catch crops for green manure, farmyard manure, and liming+leguminous catch crops+farmyard manure, whereas the soil-improving cropping systems effect was not consistent after stubble tilling in the dry year of 2018. Cross-semivariograms which used the sand content as an auxiliary variable and cokriging produced a better prediction than the semivariograms and kriging. The fractal analysis indicated that the number of subareas differing in thermal properties was mainly modified by water content and bulk density. The spatial spread of the soil thermal properties during the water-saturated and dry states increased in subareas with a higher bulk density.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46270181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. A comprehensive understanding of the uprooting failure mechanism will likely require the accurate characterization of the mechanical properties of cotton stalk. Uprooting failure includes a fractured cotton stalk and peeled phloem sliding along the xylem. The modulus of elasticity of cotton stalk and its tissues (xylem and phloem) were measured using three different modes (tensile, compression and bending), and the reasons for the fractured cotton stalk and the peeled phloem sliding along the xylem were analysed from the perspective of composite mechanics. The results showed that the cotton stalk radially conforms to the properties of the composite with transverse anisotropy. The axial modulus of elasticity was significantly larger than the radial modulus of elasticity (axial modulus of elasticity: cotton stalk is 3181.79 MPa, xylem is 1093.91 MPa, phloem is 249.89 MPa, radial modulus of elasticity: is 91.04 MPa, xylem is 83.77 MPa, phloem is 77.01 MPa). Xylem is the backbone of the stalk that provides 96% of its compressive strength. The direct cause of fractured cotton stalk originated from the load force that exceeded its intrinsic compressive strength. Peeled phloem sliding along the xylem was related for the most part to the different radial modu lus of elasticity of the xylem and phloem, and the weak cohesion between these two tissues. Based on the results, some suggestions were provided for the design of a puller.
{"title":"Investigation of mechanical properties of cotton stalk based on multi-component analyses","authors":"Wei-jun Zhao, Jianhua Xie, Zhenwei Wang, Qiming Gao, Mingjiang Chen","doi":"10.31545/intagr/152488","DOIUrl":"https://doi.org/10.31545/intagr/152488","url":null,"abstract":". A comprehensive understanding of the uprooting failure mechanism will likely require the accurate characterization of the mechanical properties of cotton stalk. Uprooting failure includes a fractured cotton stalk and peeled phloem sliding along the xylem. The modulus of elasticity of cotton stalk and its tissues (xylem and phloem) were measured using three different modes (tensile, compression and bending), and the reasons for the fractured cotton stalk and the peeled phloem sliding along the xylem were analysed from the perspective of composite mechanics. The results showed that the cotton stalk radially conforms to the properties of the composite with transverse anisotropy. The axial modulus of elasticity was significantly larger than the radial modulus of elasticity (axial modulus of elasticity: cotton stalk is 3181.79 MPa, xylem is 1093.91 MPa, phloem is 249.89 MPa, radial modulus of elasticity: is 91.04 MPa, xylem is 83.77 MPa, phloem is 77.01 MPa). Xylem is the backbone of the stalk that provides 96% of its compressive strength. The direct cause of fractured cotton stalk originated from the load force that exceeded its intrinsic compressive strength. Peeled phloem sliding along the xylem was related for the most part to the different radial modu lus of elasticity of the xylem and phloem, and the weak cohesion between these two tissues. Based on the results, some suggestions were provided for the design of a puller.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44838347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. Studies of daily changes in tree trunk diameter provide valuable information concerning growth patterns and their relationships with varying environmental conditions. To date, very few experiments with fruit trees evaluated the effects of climate variation on trunk shrinkage and the duration of the contraction and recovery phases and of growth. In this study, electronic dendrometers continuously monitored trunk diameter and trunk water storage dynamics of drip-irrigated ‘Gala’ apple trees ( Malus x domestica Borkh.) during three growing seasons, which differed significantly in temperature, precipitation, air humidity and solar irradiation. It was found that trunk diameter and meteorological variables were closely related, even when excluding the effects of soil water limitations. During each growing season, the durations of the daily contraction phase began to increase with increasing water vapour partial pressure deficit, and decreased again in autumn, when vapour partial pressure decreased. Throughout the season, the duration of the growth phase tended to change inversely to that of both contraction and recovery phase. The relationship between maximum trunk shrinkage and vapour partial pressure was higher post than preharvest for all years stud-ied. The duration of contraction, recovery, and growth phases may provide valuable information concerning seasonal changes and environmental drivers of water storage dynamics in apple trees.
树干直径的日变化研究提供了关于生长模式及其与不同环境条件的关系的有价值的信息。到目前为止，很少有果树实验评估气候变化对树干收缩、收缩和恢复阶段的持续时间以及生长的影响。在本研究中，电子树木密度计连续监测了滴灌“加拉”苹果树（Malus x domestica Borkh.）在三个生长季节的树干直径和树干蓄水动态，这三个季节在温度、降水、空气湿度和太阳辐射方面存在显著差异。研究发现，树干直径与气象变量密切相关，即使排除了土壤水分限制的影响。在每个生长季节，日收缩期的持续时间开始随着水蒸汽分压亏空的增加而增加，并在秋季蒸汽分压下降时再次减少。在整个季节中，生长期的持续时间往往与收缩期和恢复期相反。在所有年份中，采后树干最大收缩率与蒸汽分压的关系均高于采前。收缩、恢复和生长阶段的持续时间可以提供关于苹果树蓄水动态的季节变化和环境驱动因素的有价值的信息。
{"title":"Seasonal changes in dendrometer-derived stem variation in apple trees grown in temperate climate","authors":"Y. Rezaei, M. Zude-Sasse, W. Herppich","doi":"10.31545/intagr/152037","DOIUrl":"https://doi.org/10.31545/intagr/152037","url":null,"abstract":". Studies of daily changes in tree trunk diameter provide valuable information concerning growth patterns and their relationships with varying environmental conditions. To date, very few experiments with fruit trees evaluated the effects of climate variation on trunk shrinkage and the duration of the contraction and recovery phases and of growth. In this study, electronic dendrometers continuously monitored trunk diameter and trunk water storage dynamics of drip-irrigated ‘Gala’ apple trees ( Malus x domestica Borkh.) during three growing seasons, which differed significantly in temperature, precipitation, air humidity and solar irradiation. It was found that trunk diameter and meteorological variables were closely related, even when excluding the effects of soil water limitations. During each growing season, the durations of the daily contraction phase began to increase with increasing water vapour partial pressure deficit, and decreased again in autumn, when vapour partial pressure decreased. Throughout the season, the duration of the growth phase tended to change inversely to that of both contraction and recovery phase. The relationship between maximum trunk shrinkage and vapour partial pressure was higher post than preharvest for all years stud-ied. The duration of contraction, recovery, and growth phases may provide valuable information concerning seasonal changes and environmental drivers of water storage dynamics in apple trees.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41379341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zeinab Heravizadeh, Morteza Sam Daliri, M. Moballeghi, Amir Abbas Mousavi Mirkalaei
. A field experiment was conducted to evaluate the performance and water productivity of 15 rice genotypes under non-stress and drought-stress conditions in a warm-temperate cli - mate. This study was laid out with a randomized complete block design at two research stations (Abbasabad and Katalom, Iran). Water deficit decreased the grain yield and increased the canopy temperature in all genotypes, but the response of water productiv - ity to drought stress was not the same for the different genotypes. The maximum water productivity in non-stress and stress condi - tions (0.50 and 0.53 kg m –3 , respectively) were found in landraces. The canopy temperature was a reliable indicator for identifying drought-tolerant genotypes of rice. With each degree increase in canopy temperature, the grain yield decreased by 1 942 kg ha –1 . The biplot analysis demonstrated that landraces were the most suitable genotypes for cultivation under drought-stress and no-stress conditions. A principal component analysis based on stress tolerance indices showed that Shastak and Sahel were the most tolerant genotypes to drought stress. Overall, Shastak with a max - imum grain yield (4 595 kg ha –1 ), the highest water productivity, and savings of irrigation water by as much as 54% under condi - tions of drought stress may be introduced as a superior genotype for cultivation under water scarcity conditions and used in future breeding programmes.
在暖温带气候条件下，对15个水稻基因型在非胁迫和干旱胁迫条件下的表现和水分生产力进行了田间试验。本研究在两个研究站（Abbasabad和Katalom，伊朗）采用随机完全区组设计进行。水分亏缺降低了所有基因型的粮食产量，提高了冠层温度，但不同基因型的水分生产率对干旱胁迫的反应并不相同。在非胁迫和胁迫条件下（分别为0.50和0.53 kg m–3），陆地小种的水分生产率最高。冠层温度是鉴定水稻耐旱基因型的可靠指标。随着冠层温度的每升高一度，粮食产量减少1942kg ha–1。双位点分析表明，在干旱胁迫和无胁迫条件下，地方品种是最适合栽培的基因型。基于胁迫耐受指数的主成分分析表明，Shastak和Sahel是最能耐受干旱胁迫的基因型。总的来说，沙斯塔克具有最高的粮食产量（4955 kg ha–1）、最高的水生产力和在干旱胁迫条件下可节约54%的灌溉用水，可以作为缺水条件下栽培的优良基因型引入，并用于未来的育种计划。
{"title":"Effect of water stress on yield stability, water productivity, and canopy temperature of rice genotypes","authors":"Zeinab Heravizadeh, Morteza Sam Daliri, M. Moballeghi, Amir Abbas Mousavi Mirkalaei","doi":"10.31545/intagr/151642","DOIUrl":"https://doi.org/10.31545/intagr/151642","url":null,"abstract":". A field experiment was conducted to evaluate the performance and water productivity of 15 rice genotypes under non-stress and drought-stress conditions in a warm-temperate cli - mate. This study was laid out with a randomized complete block design at two research stations (Abbasabad and Katalom, Iran). Water deficit decreased the grain yield and increased the canopy temperature in all genotypes, but the response of water productiv - ity to drought stress was not the same for the different genotypes. The maximum water productivity in non-stress and stress condi - tions (0.50 and 0.53 kg m –3 , respectively) were found in landraces. The canopy temperature was a reliable indicator for identifying drought-tolerant genotypes of rice. With each degree increase in canopy temperature, the grain yield decreased by 1 942 kg ha –1 . The biplot analysis demonstrated that landraces were the most suitable genotypes for cultivation under drought-stress and no-stress conditions. A principal component analysis based on stress tolerance indices showed that Shastak and Sahel were the most tolerant genotypes to drought stress. Overall, Shastak with a max - imum grain yield (4 595 kg ha –1 ), the highest water productivity, and savings of irrigation water by as much as 54% under condi - tions of drought stress may be introduced as a superior genotype for cultivation under water scarcity conditions and used in future breeding programmes.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49367648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. The modelling of peatland functioning requires detailed knowledge of the peat structure. To this end, freezing is nowadays increasingly used to obtain X-ray micro comput ed tomography (X-ray -CT) images. The aim of this study was to analyze the structure of a peat material before freezing and post-defreezing using X-ray -CT and to look for possible alter ations in the structure by analyzing the air-filled porosity. A highly decomposed peat material close to water saturation was selected for study. Three samples were analyzed before freezing and post-defreezing using an X-ray -CT Nanotom 180NF. Results showed that the continuity and cross section of the air-filled tubu lar pores several hundreds to about one thousand micrometers in diameter were altered post-defreezing. Many much smaller air-filled pores not detected before freezing were also recorded post-defreezing. Detailed analysis showed a dramatic increase in the number of air-filled pores ranging between 1 voxel (216 10 3 µm 3 ) and 50 voxels (10.8 10 6 µm 3 ) in volume. The volume of these pores newly occupied by air using X-ray -CT and their total volume was found to be consistent with the one calculated as resulting from the increase in the specific volume of water when it turns into ice.
{"title":"Evaluation of the impact of freezing technique on pore-structure characteristics\u0000of highly decomposed peat using X-ray micro-computed tomography","authors":"H. Al Majou, A. Bruand, O. Rozenbaum, E. Le Trong","doi":"10.31545/intagr/152057","DOIUrl":"https://doi.org/10.31545/intagr/152057","url":null,"abstract":". The modelling of peatland functioning requires detailed knowledge of the peat structure. To this end, freezing is nowadays increasingly used to obtain X-ray micro comput ed tomography (X-ray -CT) images. The aim of this study was to analyze the structure of a peat material before freezing and post-defreezing using X-ray -CT and to look for possible alter ations in the structure by analyzing the air-filled porosity. A highly decomposed peat material close to water saturation was selected for study. Three samples were analyzed before freezing and post-defreezing using an X-ray -CT Nanotom 180NF. Results showed that the continuity and cross section of the air-filled tubu lar pores several hundreds to about one thousand micrometers in diameter were altered post-defreezing. Many much smaller air-filled pores not detected before freezing were also recorded post-defreezing. Detailed analysis showed a dramatic increase in the number of air-filled pores ranging between 1 voxel (216 10 3 µm 3 ) and 50 voxels (10.8 10 6 µm 3 ) in volume. The volume of these pores newly occupied by air using X-ray -CT and their total volume was found to be consistent with the one calculated as resulting from the increase in the specific volume of water when it turns into ice.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47393293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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