Soil water regimes of rotationally grazed perennial and annual forages

1999 ◽  
Vol 79 (4) ◽  
pp. 627-637 ◽  
Author(s):  
D. A. Twerdoff ◽  
D. S. Chanasyk ◽  
M. A. Naeth ◽  
V. S. Baron ◽  
E. Mapfumo

To maintain a sustainable agricultural system, management practices such as grazing must ensure adequate soil water for plant growth, yet minimize the risk of soil erosion. The objective of this study was to characterize the soil water regime of perennial and annual forages under three grazing intensities (heavy, medium and light). The study was conducted at the Lacombe Research Station, Alberta, on an Orthic Black Chernozem of loam to silt loam texture. The forages used were smooth bromegrass (Bromus inermis L. 'Carlton'), meadow bromegrass (Bromus riparius L. 'Paddock'), a mixture of triticale (X Triticosecale Wittmack 'Pika') and barley (Hordeum vulgare L. 'AC Lacombe') and triticale. Soil water measurements were conducted between April and October of 1994 and 1995 using a neutron scattering hydroprobe to a depth of 90 cm. Surface (0–7.5 cm) soil water was more responsive to grazing intensity than soil water accumulated to various depths. For all grazing treatments and forages, both surface soil water and accumulated soil water generally fluctuated between field capacity and wilting point during the growing season. Although plant water status was not determined, no visual permanent wilting of forages was observed during the study. Differences in evapotranspiration (ET), as determined by differences in soil water were evident among forage species but not grazing intensities, with perennials having high ET in spring and annuals having high ET in summer. Estimated values of water-use efficiency (WUE) were greater for perennials than for annuals and grazing effects on WUE were minimal. From a management perspective, grazing of annuals and perennials altered soil water dynamics but still maintained adequate soil water for plant growth. Key words: Evapotranspiration, forages, grazing intensity, water-use efficiency

Author(s):  
Xu Dou ◽  
Haibin Shi ◽  
Ruiping Li ◽  
Qingfeng Miao ◽  
Feng Tian ◽  
...  

Controlled drainage (CD) is an important agricultural measure for maintaining soil moisture and nutrients, controlling groundwater level, and increasing crop yield. In arid regions, CD can be used to improve the water supply in agriculture and reduce environmental pollution. In this study, we investigated the effect of CD, including a drainage depth of 40 cm (CWT1) and 70 cm (CWT2) during the plant growth period, free drainage (FD), and open ditch drainage (OD) on the migration of water, nutrients, and salts in the soil; the dynamics of groundwater level; the loss of soil nitrogen; and the growth of oilseed sunflower plants. Compared with FD, CD increased the water and nutrient content in the soil, reduced nitrogen loss, and enhanced the ability of the soil to continuously supply nitrogen to the oilseed sunflower plants, which benefited plant growth at later growth stages and reduced environmental pollution. During the period between irrigation at the budding stage and harvest stage, the average soil water content in the 0–20 cm soil layer in CWT1 increased by 3.67%, 4.78%, and 0.55%, respectively, compared with that in CWT2, FD, and OD. The soil mineral content in CWT1 was 25.17%, 35.05%, and 17.78% higher than that in CWT2, FD, and OD, respectively, indicating that higher soil salinity occurred at the later stage of plant growth in CWT1, which actually had little effect on the plants due to their enhanced salt tolerance and increased need for water and nutrients at that stage. In addition, CD delayed the decline in groundwater level, which allowed the plants to use groundwater at later growth stages, and as a result the yield and water use efficiency were improved. CWT1 significantly increased oilseed sunflower yield by 4.52–11.14% and increased water use efficiency by 1.16–10.8%. Moreover, CWT1 also increased the survival rate of the oilseed sunflower plants by 2.62–2.92%, and the plants demonstrated good growth. Therefore, under CD conditions, plants used soil water and nitrogen more efficiently and, as a result, their productivity was increased, and the water quality was improved.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 862
Author(s):  
Ignacio Tortosa ◽  
Jose M. Escalona ◽  
Guillermo Toro ◽  
Cyril Douthe ◽  
Hipolito Medrano

Climate change threatens worldwide grapevine production, especially in Mediterranean areas. To assume this challenge, the replacement of plant material to choose one more adapted to the new environmental conditions has been proposed as one of the possible solutions. Thus, the study of genetic variability in water-use efficiency (WUE) is needed to guarantee the survival of viticulture in those critical areas. In this study, the variability of WUE in 23 Tempranillo clones growth in pots and submitted to well-watered conditions and moderate water stress was studied along two consecutive years. Leaf net photosynthesis (AN), stomatal conductance (gs), and plant growth parameters were measured, in addition the instrisic WUE (AN/gs), biomass production, and water consumed were calculated. Results show a clear genotype effect for most of the studied parameters, but, with an important year by year variability. We identified different clonal behavior in response to soil water availability, that permits to classify them as water-savers vs water-spenders. In general, there was no found relationship between leaf and plant WUE, even some genotypes as 232 or 1048 were coincident in higher leaf WUE showed highly productive in terms of biomass accumulation per unit of water applied.


2007 ◽  
Vol 87 (4) ◽  
pp. 815-827 ◽  
Author(s):  
C. A. Campbell ◽  
R. P. Zentner ◽  
P. Basnyat ◽  
H. Wang ◽  
F. Selles ◽  
...  

In the semiarid prairie, available water is the most limiting and nitrogen the second most limiting factor influencing crop production. Although numerous studies have been conducted on the effect of management practices on water use efficiency (WUE), most have concentrated on monoculture wheat, the major crop grown in the region. Even those studies dealing with other crop types have mostly been short-term in nature. But precipitation is so variable in amount and distribution that such an assessment is best conducted in long-term experiments. We used the results of a 21-yr experiment, conducted in the Brown soil zone at Swift Current, Saskatchewan, to determine the influence of crop type on WUE, and used the distribution of water and NO3-N in the soil, and N uptake by the crop to assist in interpreting these results. Four crop rotations were compared: summer fallow-wheat-wheat (F-W-W), F-flax-W (F-Flx-W), continuous wheat (Cont W) and wheat-lentil (W-Lent). All received N and P fertilizer based on soil test. In the following presentation, the rotation phase shown in parentheses was the phase referred to. We used water and NO3-N measured in consecutive 0.3-m depth segments to 1.2 m in the soil, taken just prior to seeding and after harvest, and precipitation, to make this assessment. About 10 mm more water was conserved in the F-W-W rotation than in the F-Flx-W system during the 21-mo summer fallow period, and most of this difference in water was located in the 0.3- to 0.9-m depth. Soil water in the profile was 14 mm greater following flax harvest than following wheat harvest (mostly located in 0.6- to 1.2-m depth), because flax produces less biomass and has shorter roots than wheat. At harvest, wheat dried the soil to near the wilting point (154 mm), but flax and lentil left about 10 mm of available water in the profile (mostly in the 0.6- to 1.2-m depth), suggesting shallower rooting depths. Over the 9-mo winter period about 58 mm of water was stored in the soil after wheat and 41 mm after flax. Wheat stubble conserved more overwinter water than flax stubble because of its taller height. Lentil, with its much shorter stubble, conserved about 7 mm less water than wheat during winter. Because flax produces much less biomass and withdraws less N from the soil than wheat, it left more NO3-N in the soil (27 kg ha-1 more at seeding and 23 kg ha-1 more at harvest); most of the extra NO3 was in the 0.3- to 1.2-m depth reflecting flax's shallower roots. During the 9-mo overwinter period, 16 kg ha-1 of NO3-N was mineralized following wheat and 33 kg ha-1 following flax. In the spring, Cont W and stubble wheat in F-W-(W) had about 50% as much soil NO3-N as the W-Lent rotation, reflecting the cumulative benefits of N2 fixation by the pulse crop over the years . By harvest, soil NO3-N under (W)-Lent > W-(Lent) > F-Flx-(W) > F-W-(W) > Cont W. The excess NO3-N in the (W)-Lent compared to W-(Lent) was located in the 0- to 0.6-m depth suggesting excessive fertilizer application to the wheat phase of this rotation and implying a need for agronomists to reassess the criteria used for N recommendations for rotations containing pulse crops. Lentil used as much water as wheat even though its biomass was much less. WUE for wheat grown on summer fallow averaged 8.11 kg ha -1 mm-1, and for wheat grown on stubble 6.9 kg ha-1 mm-1. WUE for wheat was also higher when it followed flax than when it followed wheat. The WUE of flax and lentil averaged 50% and 64%, respectively, of wheat following wheat. A more meaningful way of expressing the efficiency of water use is as precipitation required per unit of produce from the complete cropping system (PUE). The PUE increased with cropping intensity on a yield basis (kg ha-1 mm-1): Cont W (4.6) > W-Lent (4.2) > F-W-W (4.1) > F-Flx-W (2.9) (opposite response to WUE). When PUE was calculated on a dollars produced per rotation basis ($ ha-1 mm-1): W-Lent (1.0) was higher than the other three rotations (0.6 to 0.7). Key words: Soil water, soil nitrate, lentil, flax, wheat, crop rotation, precipitation use efficiency


2021 ◽  
Vol 13 (17) ◽  
pp. 9835
Author(s):  
Xu Dou ◽  
Haibin Shi ◽  
Ruiping Li ◽  
Qingfeng Miao ◽  
Feng Tian ◽  
...  

Controlled drainage (CD) is an important agricultural measure for maintaining soil moisture and nutrients, controlling groundwater level, and increasing crop yield. In arid regions, CD can be used to improve the water supply in agriculture and reduce environmental pollution. In this study, we investigated the effects of CD, including drainage depths of 40 cm (CWT1) and 70 cm (CWT2) during the plant growth stages, free drainage (FD), and open-ditch drainage (OD), on the migration of water, nutrients, and salts in the soil, the dynamics of the groundwater level, the loss of soil nitrogen, and the growth of oilseed sunflower plants. Compared with FD, CD increased the water and nutrient content in the soil, reduced nitrogen loss, and enhanced the ability of the soil to continuously supply nitrogen to the oilseed sunflower plants, which benefited plant growth at later growth stages and reduced environmental pollution. During the period between irrigation at the budding stage and the harvest stage, the average soil water content in the 0–20 cm soil layer in CWT1 increased by 3.67%, 4.78%, and 0.55%, respectively, compared with that in CWT2, FD, and OD. The soil mineral content in CWT1 was 25.17%, 35.05%, and 17.78% higher than that in CWT2, FD, and OD, respectively, indicating that higher soil salinity occurred at the later stage of plant growth in CWT1, which actually had little effect on the plants due to their enhanced salt tolerance and increased need for water and nutrients at that stage. In addition, CD delayed the decline in groundwater level, which allowed the plants to use groundwater at later growth stages, and as a result, the yield and water-use efficiency were improved. CWT1 significantly increased oilseed sunflower yield by 4.52–11.14% and increased water-use efficiency by 1.16–10.8%. Moreover, CWT1 also increased the survival rate of the oilseed sunflower plants by 2.62–2.92%, and the plants demonstrated good growth. Therefore, under CD conditions, plants used soil water and nitrogen more efficiently and, as a result, their productivity was increased, and the water quality was improved.


2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Wafaa Abd El-Bary ◽  
Mahmoud Hegazi ◽  
Khaled El-Bagoury ◽  
Wael Sultan ◽  
Manal Mubarak

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