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Deconstructing agronomic resource use efficiencies to increase food production

Porter, JR
Thorburn, PJ
Brown, HE
Teixeira, EI
Moot, Derrick
Mills, A
Christensen, S
Date
2021-03-22
Type
Journal Article
Fields of Research
ANZSRC::300202 Agricultural land management , ANZSRC::300403 Agronomy , ANZSRC::300406 Crop and pasture improvement (incl. selection and breeding) , ANZSRC::300201 Agricultural hydrology , ANZSRC::300204 Agricultural management of nutrients , ANZSRC::3002 Agriculture, land and farm management
Abstract
Food production per unit land area needs to be increased, thus cropping systems need to use nutrients, water and solar radiation at as close to maximal efficiencies as possible. We deconstruct these efficiencies into their components to define a theoretical crop ideosystem, in which all resource use efficiencies are maximised. This defines an upper biological limit to food production. We then quantify the difference between maximum use efficiencies and those observed in three agronomic systems (maize, cocksfoot, sugarcane) and identify how, in actual farm systems, efficiencies can be raised to raise food production. We find that crop nutrient use efficiency can be limited by low water availability; thus adding nutrients would not raise production but adding water would. The converse situation of water use efficiency being affected by nutrition is not as evident. Ideosystem thinking can be used to define small- and large-scale agronomic systems that optimize water and nutrient use to maximise food production.