Author: Ackello-OgutuPublisher:
ISBN:
Category :
Languages : en
Pages : 456
Book Description
A Test of the Nutrient Non-substitution Hypothesis in Crop Response and Fertilizer Carryover Analysis
Author: Ackello-OgutuEstimation of Water and Nitrogen Crop Response Functions
Author: Sadi Sergio GrimmPublisher:
ISBN:
Category : Irrigation
Languages : en
Pages : 312
Book Description
Since the 1950's the use of polynomial production functions has become almost a standard approach to describe crop response to fertilizers and irrigation water, particularly among agricultural economists. The appropriateness of the polynomial forms is supported on basis of their good predictive ability, since high R2s are usually obtained. They have been used, however, as an approximation tool rather than based on some justification from a theoretical standpoint and, in fact, they contradict the principle of nonsubstitution among essential elements in physiological processes. This study submits to a rigorous hypothesis test the polynomial forms against a factor nonsubstitution model specification in terms of their appropriateness in describing crop response toirrigation water and nitrogen. The polynomial forms used are the quadratic, the three halves and the square root, which are estimated by using conventional multiple linear regression procedures. The basic specification for the factor nonsubstitution model consisted in assuming a linear response with a sharp transition to a plateau type maximum. This linear-plateau specification incorporates the principles of the "law of the minimum", proposed by von Liebig circa 1840. However, several other alternative formulations, assuming nonlinear output increases, are also studied. ...
A.P. Giannini and the Giannini Foundation of Agricultural Economics
Author: Giannini Foundation of Agricultural EconomicsPublisher: Giannini Foundation of Agricultural Economics University of California
ISBN:
Category : Agriculture
Languages : en
Pages : 422
Book Description
Annals of the Giannini Foundation of Agricultural Economics
Author: Giannini Foundation of Agricultural EconomicsPublisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 42
Book Description
African Crop Science Conference Proceedings
Author: East African Agricultural Journal of Kenya, Tanganyika, Uganda and Zanzibar
Author: World Agricultural Economics and Rural Sociology Abstracts
Author: Pollution Abstracts
Author: Publisher:
ISBN:
Category : Pollution
Languages : en
Pages : 814
Book Description
Indexes material from conference proceedings and hard-to-find documents, in addition to journal articles. Over 1,000 journals are indexed and literature published from 1981 to the present is covered. Topics in pollution and its management are extensively covered from the standpoints of atmosphere, emissions, mathematical models, effects on people and animals, and environmental action. Major areas of coverage include: air pollution, marine pollution, freshwater pollution, sewage and wastewater treatment, waste management, land pollution, toxicology and health, noise, and radiation.
American Doctoral Dissertations
Author: Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 564
Book Description
Save and Grow
Author: Food and Agriculture Organization of the United Nations Publisher: Food & Agriculture Org.
ISBN: 9251068712
Category : Technology & Engineering
Languages : en
Pages : 116
Book Description
The book offers a rich toolkit of relevant, adoptable ecosystem-based practices that can help the world's 500 million smallholder farm families achieve higher productivity, profitability and resource-use efficiency while enhancing natural capital.