Soybean yield in relation to distance from the Itaipu reservoir

Rogério Teixeira De Faria,Simone Silmara Werner,Gerrit Hoogenboom,Ruy Casão Junior,Luiz Antônio Zanão Junior

doi:10.1007/s00484-015-1093-8

Abstract

Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.Electronic supplementary materialThe online version of this article (doi:10.1007/s00484-015-1093-8) contains supplementary material, which is available to authorized users.

Highlights

The crop yield at sites neighboring small water bodies, such as artificial reservoirs, may be affected by microclimatic alterations caused by the presence of the water mass (Klaić and Kvakić 2014)
Soybean yield varied according to transect, crop season, cultivar, and distance from the reservoir (Fig. 3), with stable yields throughout the crop seasons and higher means observed among the transects in GUA (3947 kg ha−1), intermediate mean yields observed in Santa Terezinha de Itaipu (STI) (3485 kg ha−1), and lower mean yields observed in Santa Helena (SHE) (3214 kg ha−1)
Experiments conducted during 4 years, with two cultivars and considering three transects with five distances from the Itaipu reservoir, provided data for comparison between soybean yields at sites closer to the reservoir and yields from sites farther away in each transect

Summary

Introduction

The crop yield at sites neighboring small water bodies, such as artificial reservoirs, may be affected by microclimatic alterations caused by the presence of the water mass (Klaić and Kvakić 2014). Reports in the scientific literature on large water bodies (Sanderson 2004 and Awange and Osienala, 2006) or even small artificially created reservoirs (Klaić and Kvakić 2014) indicated that these water bodies can affect the microclimate of adjacent areas, altering the weather conditions throughout the day. The different thermodynamic characteristics between land and water results in a thermal gradient that promotes circulation of air masses by lake breezes, which mainly alter air temperature and humidity (Crosman and Horel 2010) and affect crop growth at the neighboring sites (Sanderson 2004)

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