Lucerne in crop rotations on the Riverine Plains. 2. Biomass and grain yields, water use efficiency, soil nitrogen, and profitability

2001 ◽  
Vol 52 (2) ◽  
pp. 279 ◽  
Author(s):  
J. R. Hirth ◽  
P. J. Haines ◽  
A. M. Ridley ◽  
K. F. Wilson
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Growing Season ◽  
Crop Rotations ◽  
Annual Rainfall ◽  
Continuous Cropping ◽  
Mineral N ◽  
Grain Yields ◽  
Use Efficiency ◽  
Summer Growth

In a field experiment in north-eastern Victoria (average annual rainfall 598 mm), the impact of 2–4 years of lucerne growth on the following 3–4 crops was assessed. Controls of continuous lucerne, annual pasture, and continuous crop were compared with 5 lucerne–crop rotations. Above-ground biomass and water use efficiency of lucerne, annual pasture, and crops were assessed, as were the soil N status, grain yields, and profitability of crops after lucerne. Lucerne grew more slowly over the autumn–spring growing season (20 kg DM/ha.day) than did annual pastures and crops (41 and 58 kg DM/ha.day, respectively), while over the spring–autumn period, it grew at a mean 26 kg DM/ha.day. The summer growth rates of lucerne were, however, highly variable (1–52 kg DM/ha.day). Despite large changes in temperature and water availability over the year, the biomass water use efficiency (WUEB) of lucerne was similar over the winter and summer growth seasons (16 and 10 kg DM/ha.mm, respectively) and averaged 13 kg DM/ha.mm for the whole year. In contrast, the WUEB of wheat, canola, and annual pasture over their respective growth seasons averaged 36, 38, and 26 kg DM/ha.mm. When calculated over a whole year, however, they were much closer to lucerne at 23, 14, and 17 kg DM/ha.mm, respectively. Autumn removal of lucerne left soils initially low in mineral N (mean 82 kg N/ha.m depth in April) for the establishment of the first crop, but this was not reflected in the subsequent N contents of crop biomass and grain. Autumn mineral N concentrations peaked 1–2 years after lucerne removal (mean 141 kg N/ha.m depth). Yields of first crops after lucerne were strongly dependent on growing season rainfall. When sowing commenced in a wet year, they were similar to, or greater than, the control, but when sown in a dry year, were substantially lower. When sowing commenced in a wet year, lucerne supplied additional N for a minimum of 2 crops. At least 3 crops were supplied with lucerne N when cropping commenced in a dry year. The inclusion of 2–3 years of lucerne into a continuous cropping sequence only decreased annual profitability by $AU40/ha. This work shows that short phases of lucerne (minimum of 3 years) followed by 3–4 crops can provide economically viable options for farmers and produce better hydrological outcomes than current annual-plant based cropping systems.

Estimating the water use efficiency of spring barley using crop models

2018 ◽  
Vol 156 (5) ◽  
pp. 628-644 ◽  
Author(s):  
E. Pohanková ◽  
P. Hlavinka ◽  
M. Orság ◽  
J. Takáč ◽  
K. C. Kersebaum ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Spring Barley ◽  
Growing Season ◽  
Above Ground Biomass ◽  
Grain Yields ◽  
Crop Models ◽  
Average Value ◽  
Ground Biomass ◽  
Use Efficiency

AbstractIn the current study, simulations by five crop models (WOFOST, CERES-Barley, HERMES, DAISY and AQUACROP) were compared for 7–12 growing seasons of spring barley (Hordeum vulgare) at three sites in the Czech Republic. The aims were to compare how various process-based crop models with different calculation approaches simulate different values of transpiration (Ta) and evapotranspiration (ET) based on the same input data and compare the outputs of these simulations with reference data. From the outputs of each model, the water use efficiency (WUE) from Ta (WUETa) and from actual ET (WUEETa) was calculated for grain yields and above-ground biomass yield. The results of the first part of the study show that the model with the Penman approach for calculating ET simulates lower actual ET (ETa) sums, at an average of 250 mm during the growing season, than other models, which use the Penman–Monteith approach and simulate 330 mm on average during the growing season. In the second part of the current study, WUE reference values in the range 1.9–2.4 kg/m3were calculated for spring barley and grain yield. Values of WUETa/WUEETacalculated from the outputs of individual models for grain yields and above-ground biomass yields ranged from 2.0/1.0 to 5.9/3.8 kg/m3with an average value of 3.2/2.0 kg/m3and from 3.9/2.1 to 10.5/6.8 kg/m3with an average value of 6.5/4.0 kg/m3, respectively. The results confirm that the average values of all models are nearest to actual values.

scholarly journals Evapotranspiration, crop coefficient and water use efficiency of coriander grown in tropical environment

2018 ◽  
Vol 36 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Vicente de PR da Silva ◽  
Inajá Francisco de Sousa ◽  
Alexandra L Tavares ◽  
Thieres George F da Silva ◽  
Bernardo B da Silva ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Crop Production ◽  
Field Experiments ◽  
Growth Parameters ◽  
Crop Coefficient ◽  
Growing Season ◽  
Tropical Environment ◽  
Mean Values ◽  
Use Efficiency

ABSTRACT The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ETc was obtained through the soil water balance method and the reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ETc and Kc were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ETc and Kc of coriander grown in tropical environment.

Water use efficiency and water use of Mediterranean annual pastures in southern Australia

1999 ◽  
Vol 50 (6) ◽  
pp. 1035 ◽  
Author(s):  
T. P. Bolger ◽  
N. C. Turner
Keyword(s):  
Water Use Efficiency ◽  
Linear Relationship ◽  
Water Use ◽  
Management Practices ◽  
Root Zone ◽  
Annual Rainfall ◽  
High Input ◽  
Deep Drainage ◽  
Pasture Production ◽  
Use Efficiency

There is a perception in the farming and research communities that annual pastures have low produc- tivity and water use, and contribute disproportionately to problems of rising watertables and dryland salinity. Our aim was to determine potential pasture production in relation to water use and the influence of management factors on this relationship. Experiments were initiated at 4 locations along a gradient of 300–1100 mm annual rainfall across the Western Australian agricultural zone. At each site a high input treatment was compared with a low input control. There was a strong linear relationship between water use and pasture production up to 440 mm of growing- season water use. After 30 mm of water use the potential pasture production was 30 kg/ha.mm. An upper limit to pasture production may be reached at about 12 000 kg/ha in this environment due to rainfall distribution patterns and soil water holding capacity in the root-zone. Although pasture production was increased by as much as 3500 kg/ha, water use was generally similar or only slightly more for high input compared with control plots. The marginally higher water use by the high input pastures resulted in an extra 18 mm of water extracted from the subsoil at one location by the end of the third season. A drier subsoil may provide a buffer for storing excess rainfall and reduce deep drainage. Estimated drainage was small at low rainfall sites so even marginal increases in water use by highly productive annual pastures could play a significant role in reducing water loss to deep drainage and mitigating water-table rise and secondary salinisation in low rainfall regions. Management practices aimed at promoting early growth and adequate leaf area should maximise water use, water use efficiency, and yield. The linear relationship defining potential pasture production provides a useful benchmark to farmers.

Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage or legumes 4. Nitrogen fixation, water use and yield of chickpea

1997 ◽  
Vol 37 (6) ◽  
pp. 667 ◽  
Author(s):  
W. M. Strong ◽  
R. C. Dalal ◽  
J. E. Cooper ◽  
J. A. Doughton ◽  
E. J. Weston ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Soil Nitrogen ◽  
N2 Fixation ◽  
Dry Matter ◽  
Zero Tillage ◽  
Tillage Practice ◽  
Sowing Time ◽  
Grain Yields ◽  
Use Efficiency

Summary. Continuous cereal cropping in southern Queensland and northern New South Wales has depleted native soil nitrogen fertility to a level where corrective strategies are required to sustain grain yields and high protein content. The objective of this study was to examine the performance of chickpea in chickpea–wheat rotations in terms of yields, water use and N2 fixation. The effects of sowing time and tillage practice have been studied. Chickpea grain yields varied from 356 kg/ha in 1995 to 2361 kg/ha in 1988; these were significantly correlated with the total rainfall received during the preceding fallow period and crop growth. Almost 48% of total plant production and 30% of total plant nitrogen were below-ground as root biomass. Mean values of water-use efficiency for grain, above-ground dry matter, and total dry matter were 5.9, 14.2 and 29.2 kg/ha.mm, respectively. The water-use efficiency for grain was positively correlated with the total rainfall for the preceding fallow and crop growth period although cultural practices modified water-use efficiency. The potential N2 fixation was estimated to be 0.6 kg nitrogen/ha.mm from 1992 total dry matter nitrogen yields assuming all of the nitrogen contained in chickpea was derived from the atmosphere. Sowing time had a much larger effect on grain yield and N2 fixation by chickpea than tillage practice (conventional tillage and zero tillage) although zero tillage generally increased grain yields. The late May–early June sowing time was found to be the best for chickpea grain yield and N2 fixation since it optimised solar energy use and water use, and minimised frost damage. Nitrogen fixation by chickpea was low, less than 40% nitrogen was derived from atmosphere, representing less than 20 kg nitrogen/ha.year. The potential for N2 fixation was not attained during this period due to below-average rainfall and high soil NO3-N accumulation because of poor utilisation by the preceding wheat crop. Increased soil NO3-N due to residual from fertiliser N applied to the preceding wheat crop further reduced N2 fixation. A simple soil nitrogen balance indicated that at least 60% of crop nitrogen must be obtained from N2 fixation to avoid continued soil nitrogen loss. This did not occur in most years. The generally negative soil nitrogen balance needs to be reversed if chickpea is to be useful in sustainable cropping systems although it is an attractive cash crop. Sowing time and zero tillage practice, possibly combined with more appropriate cultivars, to enhance chickpea biomass, along with low initial soil NO3-N levels, would provide maximum N2 fixation.

Influence of row spacing on water use and yield of rain-fed wheat (Triticum aestivum L.) in a no-till system with stubble retention

2010 ◽  
Vol 61 (11) ◽  
pp. 892 ◽  
Author(s):  
S. G. L. Kleemann ◽  
G. S. Gill
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Vegetative Growth ◽  
Growing Season ◽  
Light Interception ◽  
Row Spacing ◽  
Spike Density ◽  
Stubble Retention ◽  
Use Efficiency

A 3-year field study was undertaken to investigate the effect of row spacing on vegetative growth, grain yield and water-use efficiency of wheat. All 3 years of the study experienced 21–51% below-average rainfall for the growing season. Widening row spacing led to reduced biomass and tillers on per plant basis which could be related to the reduction in light interception by the wheat canopy in the wide rows which in turn could have reduced assimilate production. Reduction in vegetative growth in 54-cm rows translated into a significant reduction in grain yield which was strongly associated (r2 = 0.71) with the loss of spike density. The pattern of crop water use (evapotranspiration, ET) during the growing season was very similar for the three row-spacing treatments. However, there was some evidence for slightly lower ET (~5%) in 54-cm rows in two growing seasons. More importantly, there was no evidence for increased ET during the post-anthesis phase in wide rows as has been speculated by some researchers. Over the 3 years of the study, grain yield declined by 5–8% as row spacing increased from 18 to 36 cm and by a further 12–20% as row spacing increased from 36 to 54 cm. There was a consistent decline in water-use efficiency for grain (WUEG) with increasing row spacing over the 3 years. WUEG declined by 6–11% as crop spacing increased from 18 to 36 cm and declined further by 12–15% as row spacing increased to 54 cm. Lower light interception at wider row spacing could have reduced assimilate production by wheat as well as increased soil evaporation due to lower shading of the soil surface in more open canopies. Growers adopting wider row spacing on these relatively heavy textured soils are likely to experience some reduction in grain yield and WUEG. However, some growers may be prepared to accept a small yield penalty from intermediate row spacing as a trade-off for increased stubble retention and soil health.

Temperature and water availability effects on radiation and water use efficiencies in alfalfa (Medicago sativa L.)

2005 ◽  
Vol 45 (4) ◽  
pp. 383 ◽  
Author(s):  
D. J. Collino ◽  
J. L. Dardanelli ◽  
M. J. De Luca ◽  
R. W. Racca
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Water Availability ◽  
Vapour Pressure Deficit ◽  
Radiation Use Efficiency ◽  
Annual Rainfall ◽  
Forage Production ◽  
Temperature Regimes ◽  
Use Efficiency ◽  
Radiation Use

Alfalfa, the most important forage crop in Argentina, shows considerable variability in forage production caused by variations in inter-annual rainfall and intra-annual radiation and temperature regimes. Such variation may affect radiation use efficiency and water use efficiency. This paper seeks to study the effects of temperature and water availability on radiation use efficiency and water use efficiency. We conducted the experiment in Córdoba, Argentina, under irrigated and droughted conditions. Drought was imposed by mobile rainout shelters during 3 consecutive periods. We measured forage, intercepted photosynthetically active radiation and water use to calculate radiation use efficiency and water use efficiency between cuttings. Under irrigation, radiation use efficiency and water use efficiency normalised by daytime vapour pressure deficit, were not limited by mean temperature above 21.3 and 21.9°C, respectively. Below those critical values, both variables decreased consistently with temperature decrements. Under drought, radiation use efficiency tended to decrease and water use efficiency tended to increase. In addition, the relationship between relative dry matter and relative water use was not linear, as reported in previous studies for annual crops.

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