Abstract
Annual crop yield and nutrition have shown differentiated responses to modifications in soil chemical properties brought about by gypsum application. The aim of this study was to evaluate the effect of gypsum application rates on the chemical properties of a Latossolo Bruno (Clayey Oxisol), as well as on the nutrition and yield of a maize-barley succession under no-till. The experiment was set up in November 2009 in Guarapuava, Parana, Brazil, applying gypsum rates of 0.0, 1.5, 3.0, 4.5, and 6.0 Mg ha-1 to the soil surface upon sowing maize, with crop succession of barley. Gypsum application decreased the levels of Al3+ and Mg2+ in the 0.0-0.1 m layer and increased soil pH in the layers from 0.2-0.6 m depth. Gypsum application has increased the levels of Ca2+ in all soil layers up to 0.6 m, and the levels of S-SO4(2-) up to 0.8 m. In both crops, the leaf concentrations of Ca and S were increased while Mg concentrations have decreased as a function of gypsum rates. There was also an effect of gypsum rates on grain yield, with a quadratic response of maize and a linear increase for barley. Yield increases were up to 11 and 12 % in relation to control for the maximum technical efficiency (MTE) rates of 3.8 and 6.0 Mg ha-1 of gypsum, respectively. Gypsum application improved soil fertility in the profile, especially in the subsurface, as well as plant nutrition, increasing the yields of maize and barley.
Highlights
Cultivated area under no-till (NT) has significantly increased in Brazil in recent decades (Mello & Raij, 2006), totalizing more than 32 million hectares (Febrapdp, 2011)
Gypsum is not a soil acidity amendment. It is a source of Ca2+ and sulfate (SO42-), and due to its high solubility when compared to lime, it exhibits expressive mobility in the soil profile, improving the root environment in deeper layers by the supply of Ca2+ and decrease in Al3+ activity (Ramos et al, 2006) when Al3+ associates with SO42- (Caires et al, 2003)
The gypsum application rates had no significant effect on soil pH at depths of 0.0-0.1, 0.1-0.2, and 0.6-0.8 m (Figure 2a), with the same happening for H+Al in all the soil layers studied (Figure 2b)
Summary
Cultivated area under no-till (NT) has significantly increased in Brazil in recent decades (Mello & Raij, 2006), totalizing more than 32 million hectares (Febrapdp, 2011). Due to the fact that lime has lower solubility and vertical mobility in the soil profile than gypsum, especially in clayey soils (Amaral et al, 2004), subsurface layers show Al3+ toxicity and, or, Ca2+ deficiency increasingly with time, limiting root development and, decreasing water and nutrient uptake by plants, resulting in recurrent yield reduction when little or poor rainfall distribution occurs (Caires et al, 2001). Gypsum is not a soil acidity amendment It is a source of Ca2+ and sulfate (SO42-), and due to its high solubility when compared to lime, it exhibits expressive mobility in the soil profile, improving the root environment in deeper layers by the supply of Ca2+ and decrease in Al3+ activity (Ramos et al, 2006) when Al3+ associates with SO42- (Caires et al, 2003). The enhancement of soil fertility in the subsurface layers allows greater root development, favoring the uptake and recycling of nutrients, such as N, mainly in the nitrate (NO3-) form, which are carried to deeper soil layers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
