Effect of Plant‐Available Stored Soil Moisture on Corn Yield: II. Variable Climatic Conditions

Abstract

Agronomists have long been interested in how variation in soils and climate are related to crop yields. An experiment was conducted to quantify the effect of weekly plant available stored soil moisture (PASSM) during 10 weeks of the growing season on corn (Zea mays L.) yield under constant and variable climatic conditions. The objective of this study was to determine how much of the variation in corn yield was due to variations in soils and climate and to develop a model relating corn yield to soil, rainfall, and temperature which could be used to predict corn yields for other locations not studied. Plot yields from four Illinois locations (farms) for 3 years (1969–1971) were correlated with weekly PASSM, rooting depth, or available water holding capacity in the rooting zone and climatic data (rainfall and temperature). Experimental plots had high fertility and management. Weekly PASSM, rainfall, and temperature values were summed by a method similar to Fisher's polynomial technique as previously modified. Differences in corn yields due to soils, locations, and among years within locations are due to differences in climate (rainfall and temperature) and differences the ability of the soil to supply water. When correlated with rainfall and temperature data PASSM determined on a weekly basis was slightly less efficient (R2 = 0.80) than was rooting depth (R2 = 0.83) or amount of preseason water available in the rooting zone (R2 = 0.81) in explaining variations in corn yield. Equations fitted to the data should be useful models in predicting corn yields for other locations and soil conditions not studied. The model utilizing the amount of preseason water available in the rooting zone is particularly easy to utilize in predicting corn yield for other locations from soils and climatic data.

Climate Change: Effect of 1922-2002 Weather on Corn Yield for a Transect from Raymondville, TX, to Brookings, SD

“…One concern with using the model (5) that must be answered is how technology used to produce corn in 1969‐1971 in Illinois compares to technology currently used to produce corn at these 12 locations. In a prior study (8) experimental technology (4) was related to Corn‐Belt technology for the years 1968‐1972.…”

“…Both soil conditions restrict rooting depth and limit plant‐available stored soil moisture depending on the thickness of the root zone. The model explained 81% (R 2 ) of the corn yield variation for these four sites for these 3 years [see (4,5) for additional detail].…”

Amelioration of Typic and Albic Natraqualfs Using Calcium Chloride

“…Higher yields on Natraqualfs occurred in years when frequent rains replenished soil moisture above the natric horizon. Even in the most favorable rainfall year, corn yields on Natraqualf soil areas never equaled yields on Albaqualf soil areas (Leeper et al, 1974). Natraqualfs and Albaqualfs are both poorly drained soils and occur on flat to nearly flat topography (Figs.…”

“…Yields from warm-season crops grown on Natraqualf soils are usually severely reduced from what they are on adjacent Albaqualf soil areas (Leeper et al, 1974;Fig. 2).…”

“…3) than they do on Natraqualf soil areas. Plant-available stored soil moisture can be from 30% to 75% less on soils where natric horizons are present than where they are absent (Leeper et al, 1974). Leeper et al (1974) quantified corn yield differences for two Natraqualf/Albaqualf soil area locations for 3 years.…”