ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
–1 . Systems included a 2-yr. winter wheat (Triticum aestivum L.)-fallow (WF) and more intense 3-yr winter wheat-corn (Zea mays L.)-fallow and winter wheat-sorghum [Sorghum bicolor(L.) Moench]-fallow and 4-yr rotations. To quantify the effectiveness of the intensified systems at utilizing precipitation, we introduce the System-Precipitation-Storage Index (SPSI) and System-Precipitation-Use Index (SPUI). Mean SPSI values were 0.19 and 0.28 for 2- and 3-yr systems, respectively, meaning that the fallow periods in the 3-yr rotation were collectively 47% more efficient at storing precipitation than fallow in WF. Inclusion of a summer crop, such as corn or sorghum, increased the fraction of precipitation allocated to growing-season crop production (i.e., SPUI) from 0.43 in WF to 0.56 (i.e., an increase of 30%) in 3-yr systems. The gains in efficient use of precipitation with intensification resulted from (i) reducing the frequency of the inefficient fallow preceding wheat, and (ii) using water for transpiration that would otherwise be lost during fallow through soil evaporation, runoff, and deep percolation.
Type of Medium:
Electronic Resource
