Journal ArticleDOI
Rothamsted irrigation 1964–76
B. K. French,B. J. Legg +1 more
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In this paper, a series of irrigation experiments was done at Rothamsted where the soil is a flinty silty clay loam over flinted clay. But the results are compared with those obtained by Penman (1962, 1970, 1971) at Woburn where the soils are a loamy sand over sand.Abstract:
A series of irrigation experiments was done at Rothamsted where the soil is a flinty silty clay loam over flinty clay. The results are compared with those obtained by Penman (1962, 1970, 1971) at Woburn where the soil is a loamy sand over sand. The limiting deficits, Di, above which irrigation increased yields, were about 2·5 times greater at Rothamsted than at Woburn; this ratio approximates to the ratio of the water-holding capacities of the soils (– 0·1 to – 15 bar) to a depth of 1 m. The limiting deficits at Rothamsted were 80 mm for spring-sown field beans, 84 mm for main-crop potatoes, 100 mm for spring barley and 140 mm for spring and winter wheat. The responses to irrigation were not determined accurately as there were few years with a large response for any crop. However, the evidence is that the maximum response that could be expected for potatoes was 0·19 t/ha/mm water, and for grain dry matter of beans 0·006 t/ha/mm. The figure for potatoes agrees with that obtained by Penman at Woburn; the response of beans was much smaller at Rothamsted, partly because of severe attacks of broad bean stain virus.read more
Citations
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Sirius: a mechanistic model of wheat response to environmental variation
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Modelling the fate of nitrogen in crop and soil in the years following application of 15N-labelled fertilizer to winter wheat
TL;DR: In this paper, a computer model is presented that describes the flow of nitrogen between crop and soil on the field scale, and the model has a compartmental structure and runs on a weekly time-step.
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Effects of elevated CO2 and drought on wheat: testing crop simulation models for different experimental and climatic conditions
Frank Ewert,Daniel Rodriguez,Peter D. Jamieson,Mikhail A. Semenov,Rowan A. C. Mitchell,J. Goudriaan,John R. Porter,Bruce A. Kimball,Paul J. Pinter,Remigius Manderscheid,Hans-Joachim Weigel,Andreas Fangmeier,Elias Fereres,Francisco J. Villalobos +13 more
TL;DR: In this article, the effects of increasing carbon dioxide concentration [CO2] on wheat vary depending on water supply and climatic conditions, which are difficult to estimate and are often used to predict the impact of global atmospheric changes on food production.
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How Do Crops Manipulate Water Supply and Demand
TL;DR: The supply of water provided by the root system of a crop stand is defined in terms of the rate at which water is extracted by a root front moving downwards with a constant velocity, the available water per unit soil volume, and a time constant that is inversely proportional to root density.
References
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On Penman's equation for estimating regional evaporation
A. S. Thom,H. R. Oliver +1 more
TL;DR: In this article, a generalized ventilation term is proposed and a modified equation for evaporation derived, calibrated to give the same annual total for short vegetation as Penman's original version.
Journal ArticleDOI
Dryland Evaporative Flux in a Subhumid Climate: II. Plant Influences1
Joe T. Ritchie,Earl Burnett +1 more
Journal ArticleDOI
Estimating Evaporation and Transpiration from a Row Crop during Incomplete Cover1
C. B. Tanner,W. A. Jury +1 more
Journal ArticleDOI
A drought experiment using mobile shelters: the effect of drought on barley yield, water use and nutrient uptake
TL;DR: In this paper, the effect of drought on the harvest yield and its components, on water use and nutrient uptake, was investigated, and it was shown that a prolonged early drought had an exceptionally large effect on both yield and water use.