. 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":" ","pages":""},"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":"1 1","pages":""},"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":" ","pages":""},"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":" ","pages":""},"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}
O. Faloye, E. Ajayi, J. Rostek, T. Babalola, A. Fashina, R. Horn
. Studies which evaluated the aggregation effects in biochar-amended soils by determining the saturated hydraulic conductivity and water repellency, in combination with wetting/ drying scenarios are rare. Therefore, the objective of this study is to link water repellency and water retention in biochar-amended soils to the aggregation effect under different pyrolysis conditions and soil textures. Two feedstock sizes; twig and branch-based mango were pyrolysed at 550°, and were then mixed with sandy loam and silt loam at application rates of; 0, 30, 45 and 60 g kg –1 respectively. Sequentially, the soil-biochar mixtures were subjected to five wetting and drying cycles. In each of the cycles, the saturated hydraulic conductivity, and thereafter the contact angles of the soil-biochar mixtures were measured using the sessile drop approach. The results showed that biochar addition decreased the saturated hydraulic conductivity in all cycles. The rigidity effect was more pronounced in soil amended with biochar and produced using twig mango as opposed to the biochar produced using mango branch. A higher rigidity value was measured in the silt loam and sandy loam amended with twig as compared to the branch-based mango which may be attributed to aggregation processes. This also coincides with higher contact angle values and water retention values that were measured using twig as opposed to branch-based mango.
． 通过测定饱和导电性和疏水性来评估生物炭改性土壤中的聚集效应，并结合湿/干情景的研究很少。因此，本研究的目的是将生物炭改性土壤的拒水性和保水性与不同热解条件和土壤质地下的聚集效应联系起来。两种原料尺寸;在550°高温下对嫩枝和枝型芒果进行热解，然后与砂壤土和粉壤土混合，施用量为;分别为0、30、45和60 g kg -1。随后，对土壤-生物炭混合物进行了5个湿润和干燥循环。在每个循环中，使用无根滴法测量土壤-生物炭混合物的饱和水力导率和接触角。结果表明，生物炭的加入降低了各循环的饱和导电性。与使用芒果枝生产的生物炭相比，使用芒果枝进行生物炭改性的土壤的刚性效应更为明显。在粉壤土和砂壤土中测量到的刚性值较高，与枝状芒果相比，这可能归因于聚集过程。这也与用小树枝测量的接触角值和保水值相吻合，而不是用树枝测量的。
{"title":"Water hydraulics, retention and repellency; response to soil texture, biochar pyrolysis conditions and wetting/drying","authors":"O. Faloye, E. Ajayi, J. Rostek, T. Babalola, A. Fashina, R. Horn","doi":"10.31545/intagr/151025","DOIUrl":"https://doi.org/10.31545/intagr/151025","url":null,"abstract":". Studies which evaluated the aggregation effects in biochar-amended soils by determining the saturated hydraulic conductivity and water repellency, in combination with wetting/ drying scenarios are rare. Therefore, the objective of this study is to link water repellency and water retention in biochar-amended soils to the aggregation effect under different pyrolysis conditions and soil textures. Two feedstock sizes; twig and branch-based mango were pyrolysed at 550°, and were then mixed with sandy loam and silt loam at application rates of; 0, 30, 45 and 60 g kg –1 respectively. Sequentially, the soil-biochar mixtures were subjected to five wetting and drying cycles. In each of the cycles, the saturated hydraulic conductivity, and thereafter the contact angles of the soil-biochar mixtures were measured using the sessile drop approach. The results showed that biochar addition decreased the saturated hydraulic conductivity in all cycles. The rigidity effect was more pronounced in soil amended with biochar and produced using twig mango as opposed to the biochar produced using mango branch. A higher rigidity value was measured in the silt loam and sandy loam amended with twig as compared to the branch-based mango which may be attributed to aggregation processes. This also coincides with higher contact angle values and water retention values that were measured using twig as opposed to branch-based mango.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45039922","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}
. Both diffusional and non-diffusional limitation factors and their contribution to the phenomenon known as midday depression were studied; a decrease in photosynthesis due to environmental stress. Measurements of leaf gas exchange (tran spiration rate, stomatal conductance, photosynthetic rate) and related parameters (intercellular CO 2 concentration, maximum carboxylation, diffusional limitation index, leaf water potential) were determined over time from cucumber plants under constant environmental conditions. The experiment may be divided into three periods. Period 1 occurred when both photosynthetic rate and stomatal conductance increased, period 2 occurred when photosynthetic rate decreased but stomatal conductance remained constant, period 3 occurred with the decrease in both photosynthetic rate and stomatal conductance. Photosynthetic rate increased immediately, post-illumination, and reached its maxi mum value during period 1, then it decreased to half this value for the remainder of the experiment, indicating that a midday depression had occurred. During period 2, diffusional limitation index was around 50% and then increased while maximum car boxylation sharply decreased, suggesting the existence of both non-diffusional and diffusional limitations. In period 3, stomatal conductance decreased due to decreasing leaf water potential, and diffusional limitation index increased, suggesting that diffu sional limitation was dominant at this stage. Thus, it was found that there are multiple dominant factors in midday depression, and that these factors are dynamic even under constant environmental
{"title":"Contribution of diffusional and non-diffusional limitations to the midday depression of photosynthesis which varies dynamically even under constant environmental conditions","authors":"T. Tanizaki, G. Yokoyama, M. Kitano, D. Yasutake","doi":"10.31545/intagr/151055","DOIUrl":"https://doi.org/10.31545/intagr/151055","url":null,"abstract":". Both diffusional and non-diffusional limitation factors and their contribution to the phenomenon known as midday depression were studied; a decrease in photosynthesis due to environmental stress. Measurements of leaf gas exchange (tran spiration rate, stomatal conductance, photosynthetic rate) and related parameters (intercellular CO 2 concentration, maximum carboxylation, diffusional limitation index, leaf water potential) were determined over time from cucumber plants under constant environmental conditions. The experiment may be divided into three periods. Period 1 occurred when both photosynthetic rate and stomatal conductance increased, period 2 occurred when photosynthetic rate decreased but stomatal conductance remained constant, period 3 occurred with the decrease in both photosynthetic rate and stomatal conductance. Photosynthetic rate increased immediately, post-illumination, and reached its maxi mum value during period 1, then it decreased to half this value for the remainder of the experiment, indicating that a midday depression had occurred. During period 2, diffusional limitation index was around 50% and then increased while maximum car boxylation sharply decreased, suggesting the existence of both non-diffusional and diffusional limitations. In period 3, stomatal conductance decreased due to decreasing leaf water potential, and diffusional limitation index increased, suggesting that diffu sional limitation was dominant at this stage. Thus, it was found that there are multiple dominant factors in midday depression, and that these factors are dynamic even under constant environmental","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48769027","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 paper analyzes two seed extraction methods used by Polish silvicultural seed extractories. The analysis involves cone batches as well as individual cones processed in extraction cabinets. During thermal extraction, the cones were dried (10 h), moistened with water (10 min), and dried again (10 h). During thermomechanical extraction, the cones were dried for a much longer time (40 h), and then crushed in a mechanical unit (20 min). The two examined cases of seed extraction were compared in terms of the size, weight, and moisture content of the cones involved, the steps in the extraction process, as well as the quantity and quality of the obtained seeds. Each of the extractories made use of cones of a different provenance, which differed significantly from each other. In order to compare the different seed extraction methods, the same batch of cones collected from one geographic locality should be used. The results of a process analysis show that the thermal method was superior in terms of energy efficiency and duration. The seeds extracted using the two methods were of the highest quality (class I), which indicates that in both cases the extraction process was conducted appropriately and did not cause the quality of the seeds to deteriorate.
{"title":"Comparison of thermal and thermomechanical methods of seed extraction\u0000from larch cones based on two case studies","authors":"Ewa Tulska, M. Aniszewska","doi":"10.31545/intagr/150734","DOIUrl":"https://doi.org/10.31545/intagr/150734","url":null,"abstract":". The paper analyzes two seed extraction methods used by Polish silvicultural seed extractories. The analysis involves cone batches as well as individual cones processed in extraction cabinets. During thermal extraction, the cones were dried (10 h), moistened with water (10 min), and dried again (10 h). During thermomechanical extraction, the cones were dried for a much longer time (40 h), and then crushed in a mechanical unit (20 min). The two examined cases of seed extraction were compared in terms of the size, weight, and moisture content of the cones involved, the steps in the extraction process, as well as the quantity and quality of the obtained seeds. Each of the extractories made use of cones of a different provenance, which differed significantly from each other. In order to compare the different seed extraction methods, the same batch of cones collected from one geographic locality should be used. The results of a process analysis show that the thermal method was superior in terms of energy efficiency and duration. The seeds extracted using the two methods were of the highest quality (class I), which indicates that in both cases the extraction process was conducted appropriately and did not cause the quality of the seeds to deteriorate.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46584625","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}
G. Liebhard, A. Klik, C. Stumpp, A. M. Morales Santos, J. Eitzinger, R. Nolz
. Knowledge of crop water requirements and the effects of management practices on the amounts of water used for crop transpiration and that lost through soil evaporation is essential for efficient agricultural water management. Therefore, this study investigated the temporal evolution of weekly evaporation and transpiration rates under varying soil water conditions in a conventionally managed soybean field by partitioning evap otranspiration based on a water and δ 18 O-stable isotope mass balance. The estimated rates were considered in combination with vertical soil water distribution, atmospheric demand (based on crop evapotranspiration), actual evapotranspiration, and the plant development stage. This allowed for the weekly rates to be compared to the current conditions resulting from dry periods, rain or irrigation events, and the extent of the canopy. The range of weekly transpiration/evapotranspiration, from blossom to maturation, was between 0.60 (±0.11) and 0.82 (±0.10). Within this range, transpiration/evapotranspiration shifted depending on the vertical soil water distribution and meteorological conditions. During dry soil surface periods, evaporation dropped to almost zero, whereas a wet surface layer substantially increased evaporation/evapotran-spiration, even under a closed canopy. Under given conditions, the application of a few intense irrigations before the drying of the soil surface is recommended.
{"title":"Estimation of evaporation and transpiration rates under varying water availability for improving crop management of soybeans using oxygen isotope ratios of pore water","authors":"G. Liebhard, A. Klik, C. Stumpp, A. M. Morales Santos, J. Eitzinger, R. Nolz","doi":"10.31545/intagr/150811","DOIUrl":"https://doi.org/10.31545/intagr/150811","url":null,"abstract":". Knowledge of crop water requirements and the effects of management practices on the amounts of water used for crop transpiration and that lost through soil evaporation is essential for efficient agricultural water management. Therefore, this study investigated the temporal evolution of weekly evaporation and transpiration rates under varying soil water conditions in a conventionally managed soybean field by partitioning evap otranspiration based on a water and δ 18 O-stable isotope mass balance. The estimated rates were considered in combination with vertical soil water distribution, atmospheric demand (based on crop evapotranspiration), actual evapotranspiration, and the plant development stage. This allowed for the weekly rates to be compared to the current conditions resulting from dry periods, rain or irrigation events, and the extent of the canopy. The range of weekly transpiration/evapotranspiration, from blossom to maturation, was between 0.60 (±0.11) and 0.82 (±0.10). Within this range, transpiration/evapotranspiration shifted depending on the vertical soil water distribution and meteorological conditions. During dry soil surface periods, evaporation dropped to almost zero, whereas a wet surface layer substantially increased evaporation/evapotran-spiration, even under a closed canopy. Under given conditions, the application of a few intense irrigations before the drying of the soil surface is recommended.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46210596","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 of this Abstract. In tree fruit crops, the crop load is one factor that has an influence on the vegetative growth of the trees. However, since trees vary in leaf area and associated fruit bearing capacity, the number of fruit per tree alone is not sufficient to predict their vegetative growth. In the present study, it was investigated whether the leaf area to fruit ratio of trees variable in size and crop load, measured automatically with a LiDAR laser scanner, have an influence on growth properties of the annual shoots. Canopy leaf area, the number of fruit per tree and the leaf area to fruit ratio of apple trees from two commercial apple orchards of the cultivar 'Gala' grown on sandy soils were scanned with a LiDAR laser scanner over a two-year period (n=12 trees per orchard and year). Additionally, the amount of carbon partitioned to fruit and annual shoot growth was quantified for each tree in both years (n=36). No correlation between the number of fruit per tree and the canopy leaf area alone to the amount of carbon partitioned to annual shoot growth was found in both orchards. However, the carbon partitioned to fruit correlated to the leaf area to fruit ratio, while the amount of carbon partitioned to the annual shoot growth was only correlated to the leaf area to fruit ratio in the young orchard. The inter-tree variability in shoot properties has been described. Nevertheless, it was found that the leaf area to fruit ratio is a weak indicator for shoot properties in apple trees, especially in the mature orchards.
{"title":"Annual shoot growth on apple trees with variable canopy leaf area and crop load in response to LiDAR scanned leaf area to fruit ratio","authors":"M. Penzel, Nikos Tsoulias","doi":"10.31545/intagr/150761","DOIUrl":"https://doi.org/10.31545/intagr/150761","url":null,"abstract":"The of this Abstract. In tree fruit crops, the crop load is one factor that has an influence on the vegetative growth of the trees. However, since trees vary in leaf area and associated fruit bearing capacity, the number of fruit per tree alone is not sufficient to predict their vegetative growth. In the present study, it was investigated whether the leaf area to fruit ratio of trees variable in size and crop load, measured automatically with a LiDAR laser scanner, have an influence on growth properties of the annual shoots. Canopy leaf area, the number of fruit per tree and the leaf area to fruit ratio of apple trees from two commercial apple orchards of the cultivar 'Gala' grown on sandy soils were scanned with a LiDAR laser scanner over a two-year period (n=12 trees per orchard and year). Additionally, the amount of carbon partitioned to fruit and annual shoot growth was quantified for each tree in both years (n=36). No correlation between the number of fruit per tree and the canopy leaf area alone to the amount of carbon partitioned to annual shoot growth was found in both orchards. However, the carbon partitioned to fruit correlated to the leaf area to fruit ratio, while the amount of carbon partitioned to the annual shoot growth was only correlated to the leaf area to fruit ratio in the young orchard. The inter-tree variability in shoot properties has been described. Nevertheless, it was found that the leaf area to fruit ratio is a weak indicator for shoot properties in apple trees, especially in the mature orchards.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43682447","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}
Jing He, Yanzheng Liu, Tianze Wang, Weijie Chen, Bin Liu, Yunpeng Zhou, Yunkai Li
. Improving crop yield and quality, as well as water and fertilizer use efficiency in a synergetic manner is a substan tial challenge. It involves limits to the sustainable development of protected agriculture. Here, we propose a new irrigation method using nanobubble water through subsurface drip irrigation to improve the agricultural performance of crops. Experiments were conducted to evaluate the effects of nanobubble water on growth, yield, quality, irrigation water use efficiency, and the nitrogen partial productivity of greenhouse watermelon and muskmelon. The results showed that in nanobubble water conditions, reducing the amount of irrigation or fertilization by 20% had no negative impacts on the tested crops, instead there were increases in the yield, quality, irrigation water use efficiency and nitrogen partial productivity of the two crops. When irrigation and fertilization were both decreased by 20%, the irrigation water use efficiency was improved by 82.6 and 70.2%, the nitrogen partial productiv ity increased by 68.9 and 30.4%, vitamin C increased by 50.1 and 66.7% which was significant. This may be because nanobubble water reduced the redundant growth of crops, and promoted the bal ance between individual development and production. Moreover, nanobubble water finally achieved increased economic benefits by reducing the input of irrigation and fertilization. Therefore, we suggest that 80% irrigation and 80% fertilization with nanobubble water could be adopted for Cucurbitaceae in greenhouse condi tions. This method also has reference significance for reducing agricultural water input.
{"title":"Effects of nanobubble in subsurface drip irrigation on the yield, quality, irrigation water use efficiency and nitrogen partial productivity of watermelon and muskmelon","authors":"Jing He, Yanzheng Liu, Tianze Wang, Weijie Chen, Bin Liu, Yunpeng Zhou, Yunkai Li","doi":"10.31545/intagr/150413","DOIUrl":"https://doi.org/10.31545/intagr/150413","url":null,"abstract":". Improving crop yield and quality, as well as water and fertilizer use efficiency in a synergetic manner is a substan tial challenge. It involves limits to the sustainable development of protected agriculture. Here, we propose a new irrigation method using nanobubble water through subsurface drip irrigation to improve the agricultural performance of crops. Experiments were conducted to evaluate the effects of nanobubble water on growth, yield, quality, irrigation water use efficiency, and the nitrogen partial productivity of greenhouse watermelon and muskmelon. The results showed that in nanobubble water conditions, reducing the amount of irrigation or fertilization by 20% had no negative impacts on the tested crops, instead there were increases in the yield, quality, irrigation water use efficiency and nitrogen partial productivity of the two crops. When irrigation and fertilization were both decreased by 20%, the irrigation water use efficiency was improved by 82.6 and 70.2%, the nitrogen partial productiv ity increased by 68.9 and 30.4%, vitamin C increased by 50.1 and 66.7% which was significant. This may be because nanobubble water reduced the redundant growth of crops, and promoted the bal ance between individual development and production. Moreover, nanobubble water finally achieved increased economic benefits by reducing the input of irrigation and fertilization. Therefore, we suggest that 80% irrigation and 80% fertilization with nanobubble water could be adopted for Cucurbitaceae in greenhouse condi tions. This method also has reference significance for reducing agricultural water input.","PeriodicalId":13959,"journal":{"name":"International Agrophysics","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49435505","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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