In order to screen new varieties of suitable mechanical grain harvesting maize, the main agronomic traits, stem traits and harvesting traits of maize in the harvest period were studied through taking 18 main varieties...In order to screen new varieties of suitable mechanical grain harvesting maize, the main agronomic traits, stem traits and harvesting traits of maize in the harvest period were studied through taking 18 main varieties and newly-tested varieties in Liaoning Province as materials. It obtained the following results. Between different maize varieties, there was significant difference in the mechanical grain yield, and the quality difference was also significant. Ten test varieties including Tieyan 818 and Danyu 311 obtained higher yield than the control variety. The moisture content at harvesting was 26.0%-30.4%, the average moisture content was 28.22%, the average breaking rate was 6.52%, the average impurity rate was 1.91%, and the average yield loss rate was 6.33%. Danyu 212, Tieyan 58, Dika 516 and Danyu 801 had higher yield, and the grain moisture content, broken rate, impurity rate and yield loss rate were relatively low, so these varieties are suitable for promoting mechanical harvesting. Among the 8 traits surveyed, the traits positively correlated with yield were the percentage of broken stalks, degree of lodging, moisture content at harvesting, and percentage of kernel weight in ear weight, and traits negatively correlated with the yield included plant height, ear height, percentage of bare plants, and degree of lodging. Therefore, high moisture content is the main problem in the mechanical grain harvesting of maize, it is required to properly select early maturing varieties.展开更多
Eight summer maize varieties were evaluated in Funan County,Anhui Province,for yield and grain quality under mechanical grain harvest conditions in2019 growth season.ZY432,LY35 and JNK728 had higher grain yield potent...Eight summer maize varieties were evaluated in Funan County,Anhui Province,for yield and grain quality under mechanical grain harvest conditions in2019 growth season.ZY432,LY35 and JNK728 had higher grain yield potentials than FDC10,LX98,LD575,YD9953 and TT619.Postponed harvest from 28th Sept.to 11 thOct.was positively linked to the grain yield at roughly 1% of daily yield increase.Early harvest gave higher grain water content which was positively related to the percentage of broken grain as y=0.422 x-2.984(R^2=0.445),and to the percentage of foreign substance as y=0.248 x-3.245(R2=0.698).The relationship between grain water content and the rate of grain loss was negative as y=-0.052x+2.450(R^2=0.089).There was about 0.89% of grain water content decrease daily between harvests from 28^th Sept.to 4^th Oct.,and then was a‘slow-down’rate of dehydration.Grain weight was increasing for each variety when the harvest was postponed.JNK728 had the highest hundred-grain weight(HGW) and YD9953 had the lowest HGW.To make the mechanical grain harvest of summer maize feasible and acceptable,farmers need to pay attention to the adoption of proper varieties,following the suitable cultivation procedure and the improvement of mechanical facilities and operation.展开更多
Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and ass...Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.展开更多
Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage ...Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage losses. In Uganda, HSTs were first introduced in 2012. However, its use among farming households remains low today. Data were collected from 306 smallholder farmers from four districts of Northern Uganda using a pre-tested semi-structured questionnaire to understand their knowledge, use, and constraints to the adoption of hermetic storage. A multivariate Logit regression model was used to find the significance of the factors affecting adoption. Results showed low awareness and use of hermetic storage among smallholder farmers. Only 53.3% of the interviewed farmers were aware of the use of hermetic storage for grain storage. The SuperGrain bag was the most known form of hermetic storage (35.3%), followed by the Purdue Improved Crop Storage (PICS) bag (34.9%), metallic silo (15.5%), and plastic silo (14.4%). Hermetic storage use was even lower as only 17.6% of the surveyed farmers were using one or more forms of hermetic storage to store their grains. Insect pest management without chemical insecticides was the main reason (83.1%) for hermetic storage use. About 75.5% of those aware of hermetic storage had received training in the technology. Hermetic storage use in farming households led to improved food availability, household income, and nutrition. Lack of local availability (50.2%), high costs (37.8%), and inadequate knowledge (6.9%) were the main constraints hindering the adoption of hermetic storage in Northern Uganda. The logit regression models showed that only training in hermetic storage significantly (p = 0.002) affected farmers’ decision to adopt hermetic storage. Understanding the factors that constrain the adoption of HSTs could provide policymakers with important information to initiate and design policies and programs aimed at reducing crop storage losses.展开更多
A study was conducted at PAU Regional Research Station, Gurdaspur (Punjab) to investigate the design and operational parameters of threshing mechanism of conventional combine harvester for basmati crop. This study was...A study was conducted at PAU Regional Research Station, Gurdaspur (Punjab) to investigate the design and operational parameters of threshing mechanism of conventional combine harvester for basmati crop. This study was aimed to investigate the suitable changes required in the self-propelled conventional combine harvester for harvesting the basmati crop with minimum grain losses. Field evaluation of experiment was carried out to assess the influence of independent design variable <em>i.e.</em>, arrangement of spikes (AS) and independent operational parameters such as concave clearance (CC) and cylinder speed (CS). The study was aimed to enumerate various combining losses<em> viz</em>., extent of visible and invisible grain damage and threshing efficiency at different AS, CC and CS levels. The first year data recorded during 2017 were processed for the optimization during 2018. The results of the present study revealed that during 2017, maximum visible and invisible losses was 5.49% ± 0.33% and 28.07% ± 3.21%, respectively whereas after modification, these losses remained only 4.00% ± 0.80% and 24.07% ± 2.86%, respectively. The threshing efficiency remained above 99.31% ± 0.47%, for both years. Thus, optimization of combine harvester was able to save the visible grain damage by 60% to 83% and invisible grain damage by 6% to 16%, respectively during 2018 than the year 2017.展开更多
针对西北绿洲灌区小麦连作普遍、化肥施用量较大及氮素利用率低等问题,探究麦后复种绿肥对减量施氮小麦籽粒产量和氮素利用的补偿效应,以期为构建减氮小麦高效生产技术提供理论依据。本研究依托始于2018年的定位试验进行,2020-2022年期...针对西北绿洲灌区小麦连作普遍、化肥施用量较大及氮素利用率低等问题,探究麦后复种绿肥对减量施氮小麦籽粒产量和氮素利用的补偿效应,以期为构建减氮小麦高效生产技术提供理论依据。本研究依托始于2018年的定位试验进行,2020-2022年期间采集数据。试验采用裂区设计,主区设4种绿肥种植模式,即麦后分别复种毛叶苕子混播箭筈豌豆(HCV)、箭筈豌豆(CV)、油菜(R)和麦后休闲(F);副区为3种施氮水平:试区习惯施氮量(N3,180 kg hm^(–2))、习惯施氮减量20%(N2,144 kg hm^(-2))、习惯施氮减量40%(N1,108 kg hm^(-2))。研究表明,习惯施氮减量20%和40%显著降低了小麦籽粒产量和氮素吸收,但麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的籽粒产量和氮素吸收损失,且麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高小麦籽粒产量21.4%和氮素吸收6.9%(P<0.05)。麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的氮素利用率损失,且其结合减量施氮20%氮素利用率提高13.4%(P<0.05)。其补偿机制归因于:(1)麦后复种毛叶苕子混播箭筈豌豆在减量施氮40%条件下可补偿小麦氮素吸收速率,提高氮素净同化速率34.3%(P<0.05),维持穗部氮素分配,增加茎氮素转运率6.6%(P<0.05)。(2)与麦后休闲传统施氮量相比,麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高氮素平均吸收速率和氮素净同化速率7.2%和34.1%(P<0.05),增加灌浆初期至成熟期穗氮素分配6.7%(P<0.05),提高叶、茎氮素对穗的转运贡献率17.8%、8.9%(P<0.05)。因此,在干旱绿洲灌区,麦后复种毛叶苕子混播箭筈豌豆是实现小麦减氮40%的可行措施,麦后复种毛叶苕子混播箭筈豌豆结合减氮20%可通过提高小麦氮素吸收速率和氮素净同化率,提高叶、茎对穗的转运贡献率从而促进穗部氮素分配,实现小麦产量和氮素利用率双提升。展开更多
基金Supported by Program of Tieling Comprehensive Experimental Station for National Maize Industry Technology System(CARS-02-45)
文摘In order to screen new varieties of suitable mechanical grain harvesting maize, the main agronomic traits, stem traits and harvesting traits of maize in the harvest period were studied through taking 18 main varieties and newly-tested varieties in Liaoning Province as materials. It obtained the following results. Between different maize varieties, there was significant difference in the mechanical grain yield, and the quality difference was also significant. Ten test varieties including Tieyan 818 and Danyu 311 obtained higher yield than the control variety. The moisture content at harvesting was 26.0%-30.4%, the average moisture content was 28.22%, the average breaking rate was 6.52%, the average impurity rate was 1.91%, and the average yield loss rate was 6.33%. Danyu 212, Tieyan 58, Dika 516 and Danyu 801 had higher yield, and the grain moisture content, broken rate, impurity rate and yield loss rate were relatively low, so these varieties are suitable for promoting mechanical harvesting. Among the 8 traits surveyed, the traits positively correlated with yield were the percentage of broken stalks, degree of lodging, moisture content at harvesting, and percentage of kernel weight in ear weight, and traits negatively correlated with the yield included plant height, ear height, percentage of bare plants, and degree of lodging. Therefore, high moisture content is the main problem in the mechanical grain harvesting of maize, it is required to properly select early maturing varieties.
基金Supported by the Special Fund for Agro-Scientific Research of the Public Interest(201503112-12)。
文摘Eight summer maize varieties were evaluated in Funan County,Anhui Province,for yield and grain quality under mechanical grain harvest conditions in2019 growth season.ZY432,LY35 and JNK728 had higher grain yield potentials than FDC10,LX98,LD575,YD9953 and TT619.Postponed harvest from 28th Sept.to 11 thOct.was positively linked to the grain yield at roughly 1% of daily yield increase.Early harvest gave higher grain water content which was positively related to the percentage of broken grain as y=0.422 x-2.984(R^2=0.445),and to the percentage of foreign substance as y=0.248 x-3.245(R2=0.698).The relationship between grain water content and the rate of grain loss was negative as y=-0.052x+2.450(R^2=0.089).There was about 0.89% of grain water content decrease daily between harvests from 28^th Sept.to 4^th Oct.,and then was a‘slow-down’rate of dehydration.Grain weight was increasing for each variety when the harvest was postponed.JNK728 had the highest hundred-grain weight(HGW) and YD9953 had the lowest HGW.To make the mechanical grain harvest of summer maize feasible and acceptable,farmers need to pay attention to the adoption of proper varieties,following the suitable cultivation procedure and the improvement of mechanical facilities and operation.
基金supported by the Major State Basic Research Development Program of China (Grant No. 2010CB950103)the National Natural Science Foundation of China (Grant No. 41371201)the Strategic Project of Science and Technology of the Chinese Academy of Sciences (Grant No. XDA05080102)
文摘Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.
文摘Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage losses. In Uganda, HSTs were first introduced in 2012. However, its use among farming households remains low today. Data were collected from 306 smallholder farmers from four districts of Northern Uganda using a pre-tested semi-structured questionnaire to understand their knowledge, use, and constraints to the adoption of hermetic storage. A multivariate Logit regression model was used to find the significance of the factors affecting adoption. Results showed low awareness and use of hermetic storage among smallholder farmers. Only 53.3% of the interviewed farmers were aware of the use of hermetic storage for grain storage. The SuperGrain bag was the most known form of hermetic storage (35.3%), followed by the Purdue Improved Crop Storage (PICS) bag (34.9%), metallic silo (15.5%), and plastic silo (14.4%). Hermetic storage use was even lower as only 17.6% of the surveyed farmers were using one or more forms of hermetic storage to store their grains. Insect pest management without chemical insecticides was the main reason (83.1%) for hermetic storage use. About 75.5% of those aware of hermetic storage had received training in the technology. Hermetic storage use in farming households led to improved food availability, household income, and nutrition. Lack of local availability (50.2%), high costs (37.8%), and inadequate knowledge (6.9%) were the main constraints hindering the adoption of hermetic storage in Northern Uganda. The logit regression models showed that only training in hermetic storage significantly (p = 0.002) affected farmers’ decision to adopt hermetic storage. Understanding the factors that constrain the adoption of HSTs could provide policymakers with important information to initiate and design policies and programs aimed at reducing crop storage losses.
文摘A study was conducted at PAU Regional Research Station, Gurdaspur (Punjab) to investigate the design and operational parameters of threshing mechanism of conventional combine harvester for basmati crop. This study was aimed to investigate the suitable changes required in the self-propelled conventional combine harvester for harvesting the basmati crop with minimum grain losses. Field evaluation of experiment was carried out to assess the influence of independent design variable <em>i.e.</em>, arrangement of spikes (AS) and independent operational parameters such as concave clearance (CC) and cylinder speed (CS). The study was aimed to enumerate various combining losses<em> viz</em>., extent of visible and invisible grain damage and threshing efficiency at different AS, CC and CS levels. The first year data recorded during 2017 were processed for the optimization during 2018. The results of the present study revealed that during 2017, maximum visible and invisible losses was 5.49% ± 0.33% and 28.07% ± 3.21%, respectively whereas after modification, these losses remained only 4.00% ± 0.80% and 24.07% ± 2.86%, respectively. The threshing efficiency remained above 99.31% ± 0.47%, for both years. Thus, optimization of combine harvester was able to save the visible grain damage by 60% to 83% and invisible grain damage by 6% to 16%, respectively during 2018 than the year 2017.
文摘针对西北绿洲灌区小麦连作普遍、化肥施用量较大及氮素利用率低等问题,探究麦后复种绿肥对减量施氮小麦籽粒产量和氮素利用的补偿效应,以期为构建减氮小麦高效生产技术提供理论依据。本研究依托始于2018年的定位试验进行,2020-2022年期间采集数据。试验采用裂区设计,主区设4种绿肥种植模式,即麦后分别复种毛叶苕子混播箭筈豌豆(HCV)、箭筈豌豆(CV)、油菜(R)和麦后休闲(F);副区为3种施氮水平:试区习惯施氮量(N3,180 kg hm^(–2))、习惯施氮减量20%(N2,144 kg hm^(-2))、习惯施氮减量40%(N1,108 kg hm^(-2))。研究表明,习惯施氮减量20%和40%显著降低了小麦籽粒产量和氮素吸收,但麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的籽粒产量和氮素吸收损失,且麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高小麦籽粒产量21.4%和氮素吸收6.9%(P<0.05)。麦后复种毛叶苕子混播箭筈豌豆可补偿因减量施氮40%造成的氮素利用率损失,且其结合减量施氮20%氮素利用率提高13.4%(P<0.05)。其补偿机制归因于:(1)麦后复种毛叶苕子混播箭筈豌豆在减量施氮40%条件下可补偿小麦氮素吸收速率,提高氮素净同化速率34.3%(P<0.05),维持穗部氮素分配,增加茎氮素转运率6.6%(P<0.05)。(2)与麦后休闲传统施氮量相比,麦后复种毛叶苕子混播箭筈豌豆结合减量施氮20%提高氮素平均吸收速率和氮素净同化速率7.2%和34.1%(P<0.05),增加灌浆初期至成熟期穗氮素分配6.7%(P<0.05),提高叶、茎氮素对穗的转运贡献率17.8%、8.9%(P<0.05)。因此,在干旱绿洲灌区,麦后复种毛叶苕子混播箭筈豌豆是实现小麦减氮40%的可行措施,麦后复种毛叶苕子混播箭筈豌豆结合减氮20%可通过提高小麦氮素吸收速率和氮素净同化率,提高叶、茎对穗的转运贡献率从而促进穗部氮素分配,实现小麦产量和氮素利用率双提升。