Advances in precision agriculture in south-eastern Australia. III. Interactions between soil properties and water use help explain spatial variability of crop production in the Victorian Mallee

2009 ◽  
Vol 60 (9) ◽  
pp. 870 ◽  
Author(s):  
R. D. Armstrong ◽  
J. Fitzpatrick ◽  
M. A. Rab ◽  
M. Abuzar ◽  
P. D. Fisher ◽  
...  
Keyword(s):  
Root Growth ◽  
Grain Yield ◽  
Soil Properties ◽  
Soil Water ◽  
Water Use ◽  
Precision Agriculture ◽  
Crop Growth ◽  
Management Zones ◽  
Eastern Australia ◽  
Supplementary Irrigation

A major barrier to the adoption of precision agriculture in dryland cropping systems is our current inability to reliably predict spatial patterns of grain yield for future crops for a specific paddock. An experiment was undertaken to develop a better understanding of how edaphic and climatic factors interact to influence the spatial variation in the growth, water use, and grain yield of different crops in a single paddock so as to improve predictions of the likely spatial pattern of grain yields in future crops. Changes in a range of crop and soil properties were monitored over 3 consecutive seasons (barley in 2005 and 2007 and lentils in 2006) in the southern section of a 167-ha paddock in the Mallee region of Victoria, which had been classified into 3 different yield (low, moderate, and high) and seasonal variability (stable and variable) zones using normalised difference vegetation index (NDVI) and historic yield maps. The different management zones reflected marked differences in a range of soil properties including both texture in the topsoil and potential chemical-physical constraints in the subsoil (SSCs) to root growth and water use. Dry matter production, grain yield, and quality differed significantly between the yield zones but the relative difference between zones was reduced when supplementary irrigation was applied to barley in 2005, suggesting that some other factor, e.g. nitrogen (N), may have become limiting in that year. There was a strong relationship between crop growth and the use of soil water and nitrate across the management zones, with most water use by the crop occurring in the pre-anthesis/flowering period, but the nature of this relationship appeared to vary with year and/or crop type. In 2006, lentil yield was strongly related to crop establishment, which varied with soil texture and differences in plant-available water. In 2007 the presence of soil water following a good break to the season permitted root growth into the subsoil where there was evidence that SSCs may have adversely affected crop growth. Because of potential residual effects of one crop on another, e.g. through differential N supply and use, we conclude that the utility of the NDVI methodology for developing zone management maps could be improved by using historical records and data for a range of crop types rather than pooling data from a range of seasons.

Advances in precision agriculture in south-eastern Australia. V. Effect of seasonal conditions on wheat and barley yield response to applied nitrogen across management zones

2009 ◽  
Vol 60 (9) ◽  
pp. 901 ◽  
Author(s):  
M. R. Anwar ◽  
G. J. O'Leary ◽  
M. A. Rab ◽  
P. D. Fisher ◽  
R. D. Armstrong
Keyword(s):  
Grain Yield ◽  
Precision Agriculture ◽  
Wheat Yield ◽  
Barley Grain ◽  
Yield Response ◽  
Management Zones ◽  
Yield Zone ◽  
Crop Models ◽  
Eastern Australia

Spatial variability in grain yield across a paddock often indicates spatial variation in soil properties, especially in regions like the Victorian Mallee. We combined 2 years of field data and 119 years of simulation experiments (APSIM-Wheat and APSIM-Barley crop models) to simulate crop yield at various levels of N application in 4 different management zones to explore the robustness of the zones previously determined for an experimental site at Birchip. The crop models explained 96% and 67% of the observed variability in wheat and barley grain yields, with a root mean square error (RMSE) of 310 kg/ha and 230 kg/ha, respectively. The model produced consistent responses to the observed data from the field experiment in 2004 and 2005 where a high and stable yielding zone produced the highest dry matter as well as grain yield, while a low and variable zone recorded the lowest grain yield. However, from the long-term (119 years) simulation, the highest median wheat yield value was obtained on the low variable zone (2911 kg/ha) with high N fertiliser application, while the lowest was obtained on the high variable zone (851 kg/ha). Similarly, the highest barley yields (1880–3350 kg/ha) occurred on the low variable zone using the long-term simulation. In 10–20% of years the highest yield occurred in the high-yielding zones, with the variable and stable zones changing rank with interactive behaviour only under early-sown conditions. Our analyses highlight the problem of using a limited range of seasons of different weather conditions in agronomy to make strategic conclusions as the long-term simulation did not confirm the original yield zone determination. The challenge ahead is to predict in advance the seasons where application of N fertiliser will be beneficial.

scholarly journals Biochar addition alleviate the negative effects of drought and salinity stress on soybean productivity and water use efficiency

2020 ◽  
Author(s):  
Yaojun Zhang ◽  
Jiaqi Ding ◽  
Hong Wang ◽  
Lei Su ◽  
Cancan Zhao
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Salinity Stress ◽  
Crop Growth ◽  
Interactive Effects ◽  
Gaseous Exchange ◽  
Negative Effects ◽  
Use Efficiency ◽  
Effects Of Drought

Abstract Background: Environmental stress is a crucial factor restricting plant growth as well as crop productivity, thus influencing the agricultural sustainability. Biochar addition is proposed as an effective management to improve crop performance. However, there were few studies focused on the effect of biochar addition on crop growth and productivity under interactive effect of abiotic stress (e.g., drought and salinity). This study was conducted with a pot experiment to investigate the interaction effects of drought and salinity stress on soybean yield, leaf gaseous exchange and water use efficiency (WUE) under biochar addition. Results: Drought and salinity stress significantly depressed soybean phenology (e.g. flowering time) and all the leaf gas exchange parameters, but had inconsistent effects on soybean root growth and WUE at leaf and yield levels. Salinity stress significantly decreased photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate by 20.7%, 26.3%, 10.5% and 27.2%, respectively. Lower biomass production and grain yield were probably due to the restrained photosynthesis under drought and salinity stress. Biochar addition significantly enhanced soybean grain yield by 3.1-14.8%. Drought stress and biochar addition significantly increased WUE-yield by 27.5% and 15.6%, respectively, while salinity stress significantly decreased WUE-yield by 24.2%. Drought and salinity stress showed some negative interactions on soybean productivity and leaf gaseous exchange. But biochar addition alleviate the negative effects on soybean productivity and water use efficiency under drought and salinity stress. Conclusions: The results of the present study indicated that drought and salinity stress could significantly depress soybean growth and productivity. There exist interactive effects of drought and salinity stress on soybean productivity and water use efficiency, while we could employ biochar to alleviate the negative effects. We should consider the interactive effects of different abiotic restriction factors on crop growth thus for sustainable agriculture in the future.

A drought experiment using mobile shelters: the effect of drought on barley yield, water use and nutrient uptake

1978 ◽  
Vol 91 (3) ◽  
pp. 599-623 ◽  
Author(s):  
W. Day ◽  
B. J. Legg ◽  
B. K. French ◽  
A. E. Johnston ◽  
D. W. Lawlor ◽  
...  
Keyword(s):  
Grain Yield ◽  
Nutrient Uptake ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Grain Filling ◽  
Maximum Depth ◽  
Soil Water Deficit ◽  
Drought Treatment ◽  
Effects Of Drought

SummaryAutomatic mobile shelters were used to keep rain off a barley crop in a drought experiment. The treatments ranged from no water during the growing season to regular weekly irrigation. This paper reports the effect of drought on the harvest yield and its components, on water use and nutrient uptake.Drought caused large decreases in yield, and affected each component of the grain yield. The magnitude of each component varied by up to 25% between treatments, and much of the variation could be accounted for by linear regression against the mean soil water deficit in one of three periods. For the number of grains per ear, the relevant period included tillering and ear formation; for the number of ears per unit ground area, the period included stem extension and tiller death; for grain mass, the period included grain filling.The harvest yields were linearly related to water use, with no indication of a critical period of drought sensitivity. The relation of grain yield to the maximum potential soil water deficit did show that a prolonged early drought had an exceptionally large effect on both yield and water use.Two unsheltered irrigation experiments, also on barley, were made in the same year on a nearby site. The effects of drought on yield in these experiments were in good agreement with the effects observed on the mobile shelter site.When fully irrigated, the small plots under the mobile shelters used water 11% faster than larger areas of crop, because of advection. The maximum depth from which water was extracted was unaffected by the drought treatment. When 50% of the available soil water had been used the uptake rate decreased, but the maximum depth of uptake continued to increase.Measurements of crop nutrients at harvest showed that nitrogen uptake was large, because of site history, and that phosphate uptake was decreased by drought to such an extent that phosphate shortage may have limited yield.

Water use, competition, and crop production in low rainfall, alley farming systems of south-eastern Australia

2003 ◽  
Vol 54 (8) ◽  
pp. 751 ◽  
Author(s):  
Murray Unkovich ◽  
Kerrin Blott ◽  
Alex Knight ◽  
Ivan Mock ◽  
Abdur Rab ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Crop Yield ◽  
Farming Systems ◽  
Alley Farming ◽  
Annual Crop ◽  
South Eastern ◽  
Annual Crops ◽  
Eastern Australia ◽  
Perennial Shrubs

Annual crops were grown in alleys between belts of perennial shrubs or trees over 3–4 years at 3 sites across low rainfall (<450 mm) south-eastern Australia. At the two lower rainfall sites (Pallamana and Walpeup), crop grain yields within 2–5 m of shrub belts declined significantly with time, with a reduction equivalent to 45% over 9 m in the final year of cropping. At the third, wetter site (Bridgewater), the reduction in crop grain yields adjacent to tree belts was not significant until the final year of the study (12% over 11 m) when the tree growth rates had increased. The reductions in crop yield were associated with increased competition for water between the shrub or tree belts and the crops once the soil profile immediately below the perennials had dried. At all 3 sites during the establishment year, estimates of water use under the woody perennials were less than under annual crops, but after this, trends in estimates of water use of alley farming systems varied between sites. At Pallamana the perennial shrubs used a large amount of stored soil water in the second summer after establishment, and subsequently were predominantly dependent on rainfall plus what they could scavenge from beneath the adjacent crop. After the establishment year at the Walpeup site, water use under the perennial shrubs was initially 67 mm greater than under the annual crop, declining to be only 24 mm greater in the final year. Under the trees at Bridgewater, water use consistently increased to be 243 mm greater than under the adjacent annual crop by the final year. Although the shrub belts used more water than adjacent crop systems at Walpeup and Pallamana, this was mostly due to the use of stored soil water, and since the belts occupied only 7–18% of the land area, increases in total water use of these alley farming systems compared with conventional crop monocultures were quite small, and in terms of the extent of recharge control this was less than the area of crop yield loss. At the wetter, Bridgewater site, alley farming appeared to be using an increasing amount of water compared with conventional annual cropping systems. Overall, the data support previous work that indicates that in lower rainfall environments (<350 mm), alley farming is likely to be dogged by competition for water between crops and perennials.

Zero-tillage influence on canola, field pea and wheat in a dry subhumid region: Agronomic and physiological responses

1994 ◽  
Vol 74 (3) ◽  
pp. 411-420 ◽  
Author(s):  
Sylvia Borstlap ◽  
Martin H. Entz
Keyword(s):  
Grain Yield ◽  
Soil Water ◽  
Water Use ◽  
Field Pea ◽  
Water Extraction ◽  
Water Evaporation ◽  
Zero Tillage ◽  
Crop Species ◽  
Tillage System ◽  
Soil Water Extraction

Field trials were conducted over 4 site-years in southern Manitoba to compare the response of Katepwa wheat, Westar canola and Victoria field pea to zero tillage (ZT). The experimental design was a split plot with tillage system as the mainplot (ZT vs. conventional tillage (CT)) and crop species as the subplot. All crops received protection from insect, weed and disease pests. Tillage system had only a limited impact on crop dry matter accumulation or grain quality. Where differences were observed, crop performance was enhanced under ZT. Seasonal evapotranspiration (ET) was either reduced or unaffected by ZT, while ET efficiency (ETE: kg ha−1 mm−1 ET) was either increased or unchanged by the shift from CT to ZT. Higher ETE under ZT was attributed to less soil water evaporation. Significant tillage system × crop species (T × S) interactions for growth parameters, ET and ETE indicated that field pea often benefitted more than wheat or canola from ZT. A significant T × S interaction at one of the four sites indicated that water extraction between 30 and 90 cm was higher for pea and canola in the ZT compared with CT treatment, while soil water extraction by wheat was reduced under ZT. At a second site, lower ET for all three crops under ZT was attributed to reduced water use between 90 and 130 cm. Despite some effects of ZT on crop growth and water use, no significant tillage, T × S, or site × tillage interactions were observed for grain yield. It was concluded that under the conditions of this study (i.e. precipitation and temperature conditions close to the long-term average), Westar canola, Victoria field pea and Katepwa wheat were, for the most part, equally suited to ZT production. Key words: Soil water extraction, evapotranspiration efficiency, crop quality, grain yield, canopy development

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