scholarly journals Influence of Water and Nitrogen Stress on Stem Sap Flow of Tomato Grown in a Solar Greenhouse

2015 ◽  
Vol 140 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Rangjian Qiu ◽  
Taisheng Du ◽  
Shaozhong Kang ◽  
Renqiang Chen ◽  
Laosheng Wu
Keyword(s):  
Water Supply ◽  
Water Content ◽  
Sap Flow ◽  
Northwest China ◽  
Application Rate ◽  
Irrigation Scheduling ◽  
Regression Equations ◽  
Solar Greenhouse ◽  
Influence Of Water ◽  
Water Treatments

Accurate measurement of crop water use under different water and nitrogen (N) conditions is of great importance for irrigation scheduling and N management. This research investigated the effect of water and N status on stem sap flow of tomato (Solanum lycopersicum) grown in an unheated solar greenhouse in northwest China. A water experiment included sufficient water supply (T1) based on in situ water content measurement, two-thirds T1 (T2) and half T1 (T3) under a typical N application rate (N1); i.e., 57.4 g·m−2 N. The N experiment included N1, two-thirds N1 (N2), and half N1 (N3) under T2 irrigation. Results showed that deficit water supply reduced the stem sap flow by 22.1% and 42.8% in T2 and T3, respectively, compared with T1. The average daily stem sap flow between N1 and N2 was similar, and both were higher than that of N3. Significant differences between N1 or N2 and N3 were only observed on four dates (totally 34 days). Nighttime stem sap flow accounted for 6.0% to 6.9% of the daily value for the water treatments and 5.7% to 8.5% of the daily value for the N treatments. No significant differences for nighttime stem sap flow were found among water and N treatments. The daily stem sap flow was significantly and positively correlated with solar radiation, air temperature, vapor pressure deficit, and reference evapotranspiration under the water and N experiments. The slopes of the regression equations between the daily stem sap flow and these parameters were lower when soil water availability was limited, whereas the slopes of the regressions had no significant differences among N treatments. A parabolic relationship between the ratio of the daily stem sap flow of water deficit treatments to that of T1 and soil relative extractable water content was observed.

scholarly journals Study on the Response of Different Soybean Varieties to Water Management in Northwest China Based on a Model Approach

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 824
Author(s):  
Yunxuan Zhang ◽  
Sien Li ◽  
Mousong Wu ◽  
Danni Yang ◽  
Chunyu Wang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Experiments ◽  
Economic Value ◽  
Maximum Yield ◽  
Northwest China ◽  
Irrigation Amount ◽  
Water Treatments ◽  
Soil Moisture Status

Soybean is one of the major crops that is widely cultivated in Northwest China due to its high nutritional and economic value. However, drought has recently become an important factor restricting the growth of soybeans in the arid region of Northwest China and the selection of drought-resistant soybean is of importance for cooperating with drought and improving yield. In this study, three-year soybean field experiments were conducted to test the effects of different water treatments on the soil moisture status and the yield of two varieties of soybeans (Longhuang1 (LH1), Longahuang3 (LH3)). Based on the field data, the soil water content, biomass, LAI, and yield were calibrated and evaluated using the soil-crop system model WHCNS (soil Water Heat Carbon Nitrogen Simulator). The results showed that the nRMSE, NSE, IA, and R2 of the soil water content from two types of soybean, i.e., LH1 (LH3) were 10.98% (9.79%), 0.86 (0.90), 0.96 (0.97), 0.87 (0.90), respectively. The nRMSE, NSE, IA and R2 of the yield of LH1 (LH3) were 19.12% (4.41%), 0.87 (0.99), 0.97 (1.00), 0.98 (0.99), respectively. Scenario simulations of yield and other indicators in two soybean varieties under different irrigation schedules in different hydrological years showed that the maximum yield and II of LH3 are lower than those of LH1, but the higher yield and II of LH1 comes from a larger irrigation amount. Appropriately reducing the number of irrigations in the branching period will not reduce crop yield and may oppositely lead to a small increase in yield and income; reducing the number of irrigations at the end of grouting has no significant impact on yield and income.

Effects of soil water content and foliar fertilization with nitrogen and phosphorus in late season on the yield and composition of wheat

1979 ◽  
Vol 30 (4) ◽  
pp. 577 ◽  
Author(s):  
AM Alston
Keyword(s):  
Water Supply ◽  
Grain Yield ◽  
Water Content ◽  
Foliar Application ◽  
Nitrogen Concentration ◽  
Water Shortage ◽  
Nitrogen And Phosphorus ◽  
Effect On Yield ◽  
Water Treatments ◽  
Dough Stage

Wheat was grown in reconstructed profiles of a sandy red-brown earth in pots 120 cm deep. Ammonium sulfate (90 mg nitrogen per pot) and/or monocalcium phosphate (75 mg phosphorus per pot) were added to the topsoil. In one experiment, water treatments were introduced when the wheat reached ear emergence to provide (a) dry topsoil and water shortage; (b) dry topsoil but ample water supply in the subsoil; or (c) ample water supply, with both topsoil and subsoil wet. Additional nitrogen (82–164 mg per pot as urea) and/or phosphorus (9–18 mg per pot as phosphoric acid) were added to the plants in foliar sprays after ear emergence. In a second experiment in which water treatment (b) was applied, the dry surface soil was wetted at different stages of plant growth, viz. ear emergence, anthesis or the dough stage. In both experiments the yield and concentration of nitrogen and phosphorus in the wheat were measured at maturity. Total dry matter production was little affected by the water content of the soil after ear emergence, but grain yield was increased relative to that of straw where the topsoil was wet at the dough stage. Application of nitrogen at the time of sowing generally increased the yield of grain and straw, but phosphorus had little effect on yield. Additional foliar application of nitrogen after ear emergence increased grain yield where water stress was low: foliar application of phosphorus increased grain yield only when applied with nitrogen. Nitrogen concentration in the grain was little affected by adding nitrogen to the soil but was increased by late foliar application of nitrogen. Phosphorus concentrations were increased by phosphorus and decreased by nitrogen applications.

Evapotranspiration Measurement and Irrigation Scheduling for Several Tropical Fruit Crops Using the EnviroScan System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 549f-550
Author(s):  
Mongi Zekri ◽  
Bruce Schaffer ◽  
Stephen K. O'Hair ◽  
Roberto Nunez-Elisea ◽  
Jonathan H. Crane
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
National Parks ◽  
Quantitative Information ◽  
Irrigation Scheduling ◽  
Management Tool ◽  
Fruit Crops ◽  
Tropical Fruit

In southern Florida, most tropical fruit crops between Biscayne and Everglades National Parks are irrigated at rates and frequencies based on experience and observations of tree growth and fruit yield rather than on reliable quantitative information of actual water use. This approach suggests that irrigation rates may be excessive and could lead to leaching of agricultural chemicals into the groundwater in this environmentally sensitive area. Therefore, a study is being conducted to increase water use efficiency and optimize irrigation by accurately scheduling irrigation using a very effective management tool (EnviroScan, Sentek Environmental Innovations, Pty., Kent, Australia) that continuously monitors soil water content with highly accurate capacitance multi-sensor probes installed at several depths within the soil profile. The system measures crop water use by monitoring soil water depletion rates and allows the maintenance of soil water content within the optimum range (below field capacity and well above the onset of plant water stress). The study is being conducted in growers' orchards with three tropical fruit crops (avocado, carambola, and `Tahiti' lime) to facilitate rapid adoption and utilization of research results.

Modeling the Influence of Water Content on Soil Vapor Extraction

2003 ◽  
Vol 2 (3) ◽  
pp. 368
Author(s):  
Hongkyu Yoon ◽  
Albert J. Valocchi ◽  
Charles J. Werth
Keyword(s):  
Water Content ◽  
Soil Vapor Extraction ◽  
Vapor Extraction ◽  
Influence Of Water

scholarly journals High Phosphorus Acquisition and Allocation Strategy Is Associated with Soybean Seed Yield under Water- and P-Limited Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 574
Author(s):  
Yun-Yin Feng ◽  
Jin He ◽  
Yi Jin ◽  
Feng-Min Li
Keyword(s):  
Water Stress ◽  
Water Supply ◽  
Seed Yield ◽  
Soybean Seed ◽  
Dry Weight ◽  
Water Regimes ◽  
P Acquisition ◽  
Application Rates ◽  
Soybean Genotypes ◽  
Water Treatments

Both water stress and P deficit limit soybean seed yield, but the effects of water regimes and P application rates, their interaction on P status, acquisition, and partitioning, and their roles in yield performance have not been well-studied. Two soybean genotypes (Huangsedadou (HD) and Zhonghuang 30 (ZH)) with contrasting seed yield and root dry weight (DW) were used to investigate the P status, P acquisition, P partitioning, and yield formation under two water regimes (well-watered (WW) and cyclic water stress (WS)) and three P rates (0 (P0), 60 (P60), and 120 (P120) mg P kg−1 dry soil). The results show that increased P and water supply increased the seed yield, shoot and root DW and P concentrations and accumulations in different organs. Cultivar ZH had a significantly higher seed yield than HD at P60 and P120 under WS and at P0 under WW, but a lower seed yield at P60 and P120 under WW. Cultivar ZH had a significantly higher P harvest index and P acquisition efficiency, but a significantly lower shoot and root DW than HD. The interaction between water treatments and P rates had significant effects on leaf and stem P concentration. Cultivar ZH had significantly lower P partitioning to leaves and stems but significantly higher P partitioning to seeds than HD. The seed yield was positively correlated with leaf and seed P accumulations and P acquisition efficiency under WS. We conclude that (1) adequate water supply improved the P mobilization from leaves and stems at maturity, which may have improved the seed yield; and (2) the high P acquisition efficiency is coordination to high P partition to seeds to produce a high seed yield under water- and P-limited conditions.

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