Field experiments were conducted for two years to investigate the benefits of alternate furrow irrigation on fruit yield, quality and water use efficiency of grape （Vitis vinifera L. cv. Rizamat） in the arid region ...Field experiments were conducted for two years to investigate the benefits of alternate furrow irrigation on fruit yield, quality and water use efficiency of grape （Vitis vinifera L. cv. Rizamat） in the arid region of Northwest China. Two irrigation treatments were included, i.e., conventional furrow irrigation （CFI, two root-zones were simultaneously irrigated during the consecutive irrigation） and alternate partial root-zone furrow irrigation （AFI, two root-zones were alternatively irrigated during the consecutive irrigation）. Results indicate that AFI maintained similar photosynthetic rate （Pn） but with a reduced transpiration rate when compared to CFI. As a consequence, AFI improved water use efficiency based on evapotranspiration （WUEEr, fruit yield over water consumed） and irrigation （WUE~, fruit yield over water irrigated） by 30.0 and 34.5%, respectively in 2005, and by 12.7 and 17.7%, respectively in 2006. AFI also increased the edible percentage of berry by 2.91-4.79% significantly in both years. Vitamin C （Vc） content content of berry was increased by 25.6-37.5%, and tritrated acidity （TA） was reduced by 9.5-18.1% in AFI. This resulted in an increased total soluble solid content （TSS） to TA ratio （TSS/TA） by 11.5-16.7% when compared to CFI in both years. Our results indicate that alternate furrow irrigation is a practical way to improve grape fruit quality and water use efficiency for irrigated crops in arid areas.展开更多
This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and...This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and assimilation of lettuce plants at different root-zone temperatures (RZT). Elevated RZ [CO<sub>2</sub>] stimulated root development, root and shoot growth compared to ambient RZ [CO<sub>2</sub>]. The greatest increase in root growth was observed in plants grown under elevated RZ [CO<sub>2</sub>] of 50,000 ppm. However, RZ [CO<sub>2</sub>] of 10,000 ppm was sufficient to achieve the maximal leaf area and shoot productivity. Lettuce plants exhibited faster shoot and root growth at 20°C-RZT than at ambient (A)-RZT. However, under elevated RZ [CO<sub>2</sub>], the magnitude of increased growth was greater at A-RZT than at 20°C-RZT. Compared to RZ [CO<sub>2</sub>] of 360 ppm, elevated RZ [CO<sub>2</sub>] of 10,000 ppm increased NO<sub>3</sub>-</sup> accumulation and nitrate reductase activity (NRA) in both leaves and roots. NO<sub>3</sub>-</sup> concentrations of leaf and root were higher at 20°C-RZT than at A-RZT in all plants. NRA was higher in root than in leaf especially under A-RZT. The total reduced nitrogen (TRN) concentration was significantly higher in plants grown under elevated RZ [CO<sub>2</sub>] of 10,000 ppm than under ambient RZ [CO<sub>2</sub>] of 360 ppm with greater concentration in 20°C-RZT plants than in A-RZT plants. These results imply that elevated RZ [CO<sub>2</sub>] significantly affected root morphology, root and shoot growth and N metabolism of temperate lettuce with greater impacts at A-RZT than at 20°C-RZT. These findings have practical significance to vegetable production by growing the vegetable crops at cool-RZT with elevated RZ [CO<sub>2</sub>] to enhance its productivity.展开更多
Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone te...Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone temperatures on growth and components of hydroponically grown red leaf lettuce (Lactuca sativa L. cv. Red Wave) under a controlled cultivation system at 20°C. Compared with ambient root-zone temperature exposure, a 7-day low temperature exposure reduced leaf area, stem size, fresh weight, and water content of lettuce. However, root-zone heating treatments produced no significant changes in growth parameters compared with ambient conditions. Leaves under low root-zone temperature contained higher anthocyanin, phenols, sugar, and nitrate concentrations than leaves under other temperatures. Root oxygen consumption declined with low temperature root exposure, but not with root heating. Leaves of plants under low rootzone temperature showed hydrogen peroxide production, accompanied by lipid peroxidation. Therefore, low temperature root treatment is suggested to induce oxidative stress responses in leaves, activating antioxidative secondary metabolic pathways.展开更多
Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse e...Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be conside展开更多
Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-...Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot experiments.There were four combinations of irrigation levels and growing stages of tomato for AI,i.e.AI_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,i.e.low urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of urea.Irrigation quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,respectively.Compared to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,respectively.AI_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)significantly.Compared to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,respectively.Compared to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,respectively.Therefore,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.展开更多
Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use ...Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.展开更多
Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bot...Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content （e）, soil temperature （Ts） and leaf area （LA） were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent （SFP）, north side female parent （NFP） and male parent （MP） were investigated. The order of stem flow rate was： SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation （Rs） was the main driving factor of stem flow. The influence of air temperature （Ta） during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.展开更多
Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the g...Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the growth and production of maize(Zea mays L)in addition to the water use efficiency in soils with different gypsum content.The experimental treatments include three irrigation treatments,i.e.Conventional Irrigation(CI),Alternate Partial Root-zone Drying(APRD)and Fixed Partial Root-zone Drying(FPRD),and three soils with different gypsum content"(60.0[G1],153.7[G2],and 314.2[G3]g kg^(-1))".The vegetative growth,root dry mass and physiological indices(leaf relative water content,carotenoid concentration,proline)have been studied during three stages of maize plant growth(jointing,tasselling,and maturing).The Results showed that compared to CI,APRD and FPRD increased water use efficiency by 38.93 and 14.94%based on dry seed yield.In addition,compared to CI,APRD increased maize seed yield by 4.62-20.71%,while FPRD decreased yield by 19.24-5.28%for the gypsiferous soils G2 and G3,respectively.APRD has a slight effect on leaf water potential,leaf relative water content,carotenoid and proline activities from jointing to maturing stages at the three gypsiferous soils.Results suggest that APRD could make maize plants use water even more productively with better adaptation to water shortages in the gypsiferous soils.展开更多
Partial root-zone irrigation （PRI） has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was perfor...Partial root-zone irrigation （PRI） has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water （D2O） in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.展开更多
基金grants from the National Natural Science Foundation of China (51222905, 51079147 and 50939005)the National High-Tech R&D Program of China(863 Program, 2011AA100502)+1 种基金the Program of New Century Excellent Talents in University, Ministry of Education of China (NCET-11-0479)Hong Kong Research Grants Council, China (HKBU 262307)
文摘Field experiments were conducted for two years to investigate the benefits of alternate furrow irrigation on fruit yield, quality and water use efficiency of grape （Vitis vinifera L. cv. Rizamat） in the arid region of Northwest China. Two irrigation treatments were included, i.e., conventional furrow irrigation （CFI, two root-zones were simultaneously irrigated during the consecutive irrigation） and alternate partial root-zone furrow irrigation （AFI, two root-zones were alternatively irrigated during the consecutive irrigation）. Results indicate that AFI maintained similar photosynthetic rate （Pn） but with a reduced transpiration rate when compared to CFI. As a consequence, AFI improved water use efficiency based on evapotranspiration （WUEEr, fruit yield over water consumed） and irrigation （WUE~, fruit yield over water irrigated） by 30.0 and 34.5%, respectively in 2005, and by 12.7 and 17.7%, respectively in 2006. AFI also increased the edible percentage of berry by 2.91-4.79% significantly in both years. Vitamin C （Vc） content content of berry was increased by 25.6-37.5%, and tritrated acidity （TA） was reduced by 9.5-18.1% in AFI. This resulted in an increased total soluble solid content （TSS） to TA ratio （TSS/TA） by 11.5-16.7% when compared to CFI in both years. Our results indicate that alternate furrow irrigation is a practical way to improve grape fruit quality and water use efficiency for irrigated crops in arid areas.
文摘This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and assimilation of lettuce plants at different root-zone temperatures (RZT). Elevated RZ [CO<sub>2</sub>] stimulated root development, root and shoot growth compared to ambient RZ [CO<sub>2</sub>]. The greatest increase in root growth was observed in plants grown under elevated RZ [CO<sub>2</sub>] of 50,000 ppm. However, RZ [CO<sub>2</sub>] of 10,000 ppm was sufficient to achieve the maximal leaf area and shoot productivity. Lettuce plants exhibited faster shoot and root growth at 20°C-RZT than at ambient (A)-RZT. However, under elevated RZ [CO<sub>2</sub>], the magnitude of increased growth was greater at A-RZT than at 20°C-RZT. Compared to RZ [CO<sub>2</sub>] of 360 ppm, elevated RZ [CO<sub>2</sub>] of 10,000 ppm increased NO<sub>3</sub>-</sup> accumulation and nitrate reductase activity (NRA) in both leaves and roots. NO<sub>3</sub>-</sup> concentrations of leaf and root were higher at 20°C-RZT than at A-RZT in all plants. NRA was higher in root than in leaf especially under A-RZT. The total reduced nitrogen (TRN) concentration was significantly higher in plants grown under elevated RZ [CO<sub>2</sub>] of 10,000 ppm than under ambient RZ [CO<sub>2</sub>] of 360 ppm with greater concentration in 20°C-RZT plants than in A-RZT plants. These results imply that elevated RZ [CO<sub>2</sub>] significantly affected root morphology, root and shoot growth and N metabolism of temperate lettuce with greater impacts at A-RZT than at 20°C-RZT. These findings have practical significance to vegetable production by growing the vegetable crops at cool-RZT with elevated RZ [CO<sub>2</sub>] to enhance its productivity.
文摘Soil temperature influences crop growth and quality under field and greenhouse conditions;however, precise investigation using controlled cultivation systems is largely lacking. We investigated effects of root-zone temperatures on growth and components of hydroponically grown red leaf lettuce (Lactuca sativa L. cv. Red Wave) under a controlled cultivation system at 20°C. Compared with ambient root-zone temperature exposure, a 7-day low temperature exposure reduced leaf area, stem size, fresh weight, and water content of lettuce. However, root-zone heating treatments produced no significant changes in growth parameters compared with ambient conditions. Leaves under low root-zone temperature contained higher anthocyanin, phenols, sugar, and nitrate concentrations than leaves under other temperatures. Root oxygen consumption declined with low temperature root exposure, but not with root heating. Leaves of plants under low rootzone temperature showed hydrogen peroxide production, accompanied by lipid peroxidation. Therefore, low temperature root treatment is suggested to induce oxidative stress responses in leaves, activating antioxidative secondary metabolic pathways.
基金supported by the National Natural Science Foundation of China(51809189)the Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources,China(2019002)。
文摘Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be conside
基金This study was supported by National Natural Science Fund of China(51469010,51109102,51769010 and 51469003)Visiting Scholar Fund of Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education,Northwest A&F University.
文摘Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot experiments.There were four combinations of irrigation levels and growing stages of tomato for AI,i.e.AI_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,i.e.low urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of urea.Irrigation quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,respectively.Compared to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,respectively.AI_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)significantly.Compared to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,respectively.Compared to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,respectively.Therefore,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.
基金supported by the National Natural Science Fundation of China (51621061, 91425302) the 111 Program of Introducing Talents of Discipline to Universities (B14002)
文摘Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.
基金grants from the National Natural Science Foundation of China (51222905, 51321001, 51439006)the National High-Tech R&D Program of China (863 Program, 2011AA100505)+1 种基金the Ministry of Water Resources of China (201201003)the Program for New Century Excellent Talents in University, Ministry of Education, China (NCET11-0479)
文摘Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content （e）, soil temperature （Ts） and leaf area （LA） were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent （SFP）, north side female parent （NFP） and male parent （MP） were investigated. The order of stem flow rate was： SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation （Rs） was the main driving factor of stem flow. The influence of air temperature （Ta） during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.
文摘Alternate partial root-zone drying(APRD)is a water-saving method but can regulate crop physiological responses.A pot experiment has been conducted to study the efficiency of partial and fixed root-zone drying on the growth and production of maize(Zea mays L)in addition to the water use efficiency in soils with different gypsum content.The experimental treatments include three irrigation treatments,i.e.Conventional Irrigation(CI),Alternate Partial Root-zone Drying(APRD)and Fixed Partial Root-zone Drying(FPRD),and three soils with different gypsum content"(60.0[G1],153.7[G2],and 314.2[G3]g kg^(-1))".The vegetative growth,root dry mass and physiological indices(leaf relative water content,carotenoid concentration,proline)have been studied during three stages of maize plant growth(jointing,tasselling,and maturing).The Results showed that compared to CI,APRD and FPRD increased water use efficiency by 38.93 and 14.94%based on dry seed yield.In addition,compared to CI,APRD increased maize seed yield by 4.62-20.71%,while FPRD decreased yield by 19.24-5.28%for the gypsiferous soils G2 and G3,respectively.APRD has a slight effect on leaf water potential,leaf relative water content,carotenoid and proline activities from jointing to maturing stages at the three gypsiferous soils.Results suggest that APRD could make maize plants use water even more productively with better adaptation to water shortages in the gypsiferous soils.
基金supported by the Beijing Natural Science Foundation,China (6102006)the New-Star of Science and Technology of Beijing Metropolis,China (2011051)
文摘Partial root-zone irrigation （PRI） has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water （D2O） in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.
