Ya Ym p1 ETaETm5182

where Ya is the actual yield (kg), ETa is the actual seasonal ET (mm), Ym is the maximum yield (kg), ETm is the seasonal ET for maximum yield (mm), and p is the water-yield sensitivity coefficient. The normalization of production functions (i.e., its graphic representation) considering the grain yield and the seasonal ET in relative terms (as percentage of its maximum values) is very useful for its comparison with the results attained in other works.

Figure 5.39 represents the normalized production function for maize crops from California [61], North Dakota [62], and Zaragoza, Spain [63].

FAO adopted this model [Eq. (5.182)] to develop a method of quantifying the relationship between yield and water [64]. Ym is calculated by de Wit's [34] approach

20 40 60 80 100

20 40 60 80 100

Growing Soilless

Growing Soilless

This is an easy-to-follow, step-by-step guide to growing organic, healthy vegetable, herbs and house plants without soil. Clearly illustrated with black and white line drawings, the book covers every aspect of home hydroponic gardening.

Get My Free Ebook


Post a comment