Winter bamboo shoots are widely used in Asian cuisine. We surveyed growth depth （tail depth and root depth）, harvest speed, and harvest processes to provide information for developing new harvest technology. The tai...Winter bamboo shoots are widely used in Asian cuisine. We surveyed growth depth （tail depth and root depth）, harvest speed, and harvest processes to provide information for developing new harvest technology. The tail depth of most winter bamboo shoots was 100 350 mm below the soil surface, and the root depth was 200 500 mm below the soil surface. Most winter bamboo shoots were difficult to locate with only the naked eye. The digging depth was 200 500 mm to cut winter bamboo shoots from the root. The highest harvest rate was 7.75 times faster than the slowest one and the average harvest speed ratio of men： women was about 1.71：1. The harvest process of winter bamboo shoots was divisible into three steps： searching, digging a hole （around the shoot） and cutting the root. The ratio of searching time to the sum of digging and cutting time was about 8：1, showing that searching required more time than digging and cutting together.展开更多
The dynamic relationship of dry matter accumulation and distribution between winter wheat root and shoot was studied under different soil water conditions. The dry matter accumulation in root was greatly influenced by...The dynamic relationship of dry matter accumulation and distribution between winter wheat root and shoot was studied under different soil water conditions. The dry matter accumulation in root was greatly influenced by water stress, so as to the final root weight of the treatment with 40% field moisture capacity(FMC) was less than 1/4 of that of the treatment with 80% FMC on average. Water stress during the 3-leaf stage to the tillering stage had the greatest influence on root, and the influence of water stress during the jointing stage to the booting stage on shoot was greater than root. However, water stress during the tillering stage to the booting stage had a balanced effect on root and shoot, and the proportion of dry matter that distributed to root and shoot was almost the same after rewatering. Water recovery during the jointing stage to booting stage could promote R/S, but the increasing degree was related to the duration of water limitation. Soil water condition had the lowest effect on R/S during the flowering stage to the filling stage and the maximal effect on R/S during the jointing stage to the heading stage, R/S of 40% FMC treatment was 20.93 and 126.09% higher than that of 60% FMC and 80% FMC treatments respectively at this period.展开更多
The equilibrium between root, shoot and growth stability under different soil water conditions were investigated in a tube experiment of winter wheat. The water supplying treatments included： sufficient irrigation at...The equilibrium between root, shoot and growth stability under different soil water conditions were investigated in a tube experiment of winter wheat. The water supplying treatments included： sufficient irrigation at whole growth phase, moderate deficiency irrigation at whole growth phase, serious deficiency irrigation at whole growth phase, sufficient irrigation at jointing stage, tillering stage, flowering stage, and fillering respectively, after moderate and serious water deficit during their previous growth stage. Root and shoot biomass were measured. On the basis of the cooperative root-shoot interactions model, the equilibrium and growth stability were studied on the strength of the kinetics system theory. There was only one varying equilibrium point between the root and shoot over the life time of the winter wheat plant. Water stress prolonged the duration of stable growth, the more serious the water deficit, the longer the period of stable growth. The duration of stable growth was shortened and that of unstable growth was prolonged after water recovery. The growth behavior of the plants exposed to moderate water deficit shifted from stable to unstable until the end of the growth, after rewatering at flowering. In the life-time of the crop, the root and shoot had been adjusting themselves in structure and function so as to maintain an equilibrium, but could not achieve the equilibrium state for long. They were always in an unbalanced state from the beginning to the end of growth. This was the essence of root-shoot equilibrium. Water stress inhibited the function of root and shoot, reduced root shoot interactions, and as a result, the plant growth gradually tended to stabilize. Rewatering enhanced root shoot interactions, prolonged duration of instable growth. Rewatering at flowering could upset the inherent relativity during the long time of stable growth from flowering to filling stage, thus leading to unstable growth and enhanced dry matter accumulating rate in the whole plant.展开更多
植株根系的形态和生理特性决定着其获取养分和水分的能力,分析麦田冬小麦根系形态特征、根系活力对水氮的响应及其与地上干物质积累、产量和氮素利用的关系,有利于构建合理的冬小麦根群结构,促进根冠协调生长并提高氮肥利用效率。在麦...植株根系的形态和生理特性决定着其获取养分和水分的能力,分析麦田冬小麦根系形态特征、根系活力对水氮的响应及其与地上干物质积累、产量和氮素利用的关系,有利于构建合理的冬小麦根群结构,促进根冠协调生长并提高氮肥利用效率。在麦田定位试验基础上,采用裂区试验设计,设置2个灌溉主处理(W0:全生育期不灌水、W1:拔节期和开花期各灌水1次)以及3个施氮副处理(N0:0 kg hm^(–2)、N180:180 kg hm^(–2)和N300:300 kg hm^(–2))。结果表明:与W0处理相比,W1抑制根长密度的增加,但增加根系平均直径,提高0~20 cm土层根表面积和根干重密度,显著提高根系活力4.98%~22.7%,降低根冠比1.47%~11.25%;2年平均小麦产量、氮素吸收效率和氮肥偏生产力分别提高15.50%、13.40%和14.91%。施氮促进根系生长,与不施氮处理相比,施氮显著提高根系平均直径、根长密度、根表面积、根干重密度和根系活力,降低根冠比。其中N180更有利于根系生长,提高冬小麦根系各形态指标和根系活力,与N300相比,2年平均产量提高2.53%,而氮素吸收效率和氮肥农学效率分别显著提高44.51%和39.37%。相关分析表明,拔节期至开花期根干重密度与产量、氮利用率呈显著正相关关系;根冠比与产量呈显著负相关关系,与氮利用率呈正相关关系。因此,合理的灌水和施氮能够优化根系形态及分布,提高根系活力,协调根冠干物质分配,提高产量和氮利用率。在冬小麦生产中拔节和开花期各灌水1次结合180 kg hm^(–2)施氮量有利于促进产量和氮素利用效率协同提高。展开更多
基金support by National Science Project of China with Research Grant 30900870 and 50775079Science Project of Guangdong Province with Research Grant 07300720
文摘Winter bamboo shoots are widely used in Asian cuisine. We surveyed growth depth （tail depth and root depth）, harvest speed, and harvest processes to provide information for developing new harvest technology. The tail depth of most winter bamboo shoots was 100 350 mm below the soil surface, and the root depth was 200 500 mm below the soil surface. Most winter bamboo shoots were difficult to locate with only the naked eye. The digging depth was 200 500 mm to cut winter bamboo shoots from the root. The highest harvest rate was 7.75 times faster than the slowest one and the average harvest speed ratio of men： women was about 1.71：1. The harvest process of winter bamboo shoots was divisible into three steps： searching, digging a hole （around the shoot） and cutting the root. The ratio of searching time to the sum of digging and cutting time was about 8：1, showing that searching required more time than digging and cutting together.
基金supported by the National Natural Science Foundation of China(49971042).
文摘The dynamic relationship of dry matter accumulation and distribution between winter wheat root and shoot was studied under different soil water conditions. The dry matter accumulation in root was greatly influenced by water stress, so as to the final root weight of the treatment with 40% field moisture capacity(FMC) was less than 1/4 of that of the treatment with 80% FMC on average. Water stress during the 3-leaf stage to the tillering stage had the greatest influence on root, and the influence of water stress during the jointing stage to the booting stage on shoot was greater than root. However, water stress during the tillering stage to the booting stage had a balanced effect on root and shoot, and the proportion of dry matter that distributed to root and shoot was almost the same after rewatering. Water recovery during the jointing stage to booting stage could promote R/S, but the increasing degree was related to the duration of water limitation. Soil water condition had the lowest effect on R/S during the flowering stage to the filling stage and the maximal effect on R/S during the jointing stage to the heading stage, R/S of 40% FMC treatment was 20.93 and 126.09% higher than that of 60% FMC and 80% FMC treatments respectively at this period.
基金supported by the National Basic Research Program of China(973 Program,G1999011709)the Natural Science Foundation of Guangdong Province,China(33135).
文摘The equilibrium between root, shoot and growth stability under different soil water conditions were investigated in a tube experiment of winter wheat. The water supplying treatments included： sufficient irrigation at whole growth phase, moderate deficiency irrigation at whole growth phase, serious deficiency irrigation at whole growth phase, sufficient irrigation at jointing stage, tillering stage, flowering stage, and fillering respectively, after moderate and serious water deficit during their previous growth stage. Root and shoot biomass were measured. On the basis of the cooperative root-shoot interactions model, the equilibrium and growth stability were studied on the strength of the kinetics system theory. There was only one varying equilibrium point between the root and shoot over the life time of the winter wheat plant. Water stress prolonged the duration of stable growth, the more serious the water deficit, the longer the period of stable growth. The duration of stable growth was shortened and that of unstable growth was prolonged after water recovery. The growth behavior of the plants exposed to moderate water deficit shifted from stable to unstable until the end of the growth, after rewatering at flowering. In the life-time of the crop, the root and shoot had been adjusting themselves in structure and function so as to maintain an equilibrium, but could not achieve the equilibrium state for long. They were always in an unbalanced state from the beginning to the end of growth. This was the essence of root-shoot equilibrium. Water stress inhibited the function of root and shoot, reduced root shoot interactions, and as a result, the plant growth gradually tended to stabilize. Rewatering enhanced root shoot interactions, prolonged duration of instable growth. Rewatering at flowering could upset the inherent relativity during the long time of stable growth from flowering to filling stage, thus leading to unstable growth and enhanced dry matter accumulating rate in the whole plant.
文摘植株根系的形态和生理特性决定着其获取养分和水分的能力,分析麦田冬小麦根系形态特征、根系活力对水氮的响应及其与地上干物质积累、产量和氮素利用的关系,有利于构建合理的冬小麦根群结构,促进根冠协调生长并提高氮肥利用效率。在麦田定位试验基础上,采用裂区试验设计,设置2个灌溉主处理(W0:全生育期不灌水、W1:拔节期和开花期各灌水1次)以及3个施氮副处理(N0:0 kg hm^(–2)、N180:180 kg hm^(–2)和N300:300 kg hm^(–2))。结果表明:与W0处理相比,W1抑制根长密度的增加,但增加根系平均直径,提高0~20 cm土层根表面积和根干重密度,显著提高根系活力4.98%~22.7%,降低根冠比1.47%~11.25%;2年平均小麦产量、氮素吸收效率和氮肥偏生产力分别提高15.50%、13.40%和14.91%。施氮促进根系生长,与不施氮处理相比,施氮显著提高根系平均直径、根长密度、根表面积、根干重密度和根系活力,降低根冠比。其中N180更有利于根系生长,提高冬小麦根系各形态指标和根系活力,与N300相比,2年平均产量提高2.53%,而氮素吸收效率和氮肥农学效率分别显著提高44.51%和39.37%。相关分析表明,拔节期至开花期根干重密度与产量、氮利用率呈显著正相关关系;根冠比与产量呈显著负相关关系,与氮利用率呈正相关关系。因此,合理的灌水和施氮能够优化根系形态及分布,提高根系活力,协调根冠干物质分配,提高产量和氮利用率。在冬小麦生产中拔节和开花期各灌水1次结合180 kg hm^(–2)施氮量有利于促进产量和氮素利用效率协同提高。
