Influence of Accompanying Anions on Potassium Retention and Leaching in Potato Growing Alluvial Soils

SVMLEACH – NK POTATO: A simple software tool to simulate nitrate and potassium co-leaching under potato crop

“…The sequential forward variable selection followed the same sequence as for the NO 3 model, except that the addition of N fert had a much larger impact during training. This strong sensitivity of K leachate concentration to N fertilization rate might confirm the relationship between NO 3 and K reported by Sharma and Sharma (2013). The most performing model was obtained using the same five variables as the final NO 3 model, namely Rtemp, Rrain, DOY, N fert and % Clay.…”

“…Mean K leachate concentration was 18.4 mg L À1 . As a comparison, Sharma and Sharma (2013) reported maximal K leachate concentration between 6.40 and 9.29 mg L À1 for a K application of 144 kg ha À1 . Considering that K application rate in the current study was almost double (260 kg ha À1 ), results can be considered comparable.…”

“…Studies conducted in the North eastern part of the U.S. (Maine, New York) and Canada (Ontario) have shown that, for potato crops, 45-60% of the N applied at planting is recovered by the tubers (Bouldin and Selleck, 1977). Sharma and Sharma (2013) demonstrated that accompanying anions such as Cl À and NO 3 À may also lead to substantial K losses, especially in light textured soils. Although K is not usually considered an environmental pollutant, its leaching may also affect plant growth and quality (Broschat, 1995).…”

Variations in the chemical composition of the solution extracted from a Latosol under fertigation with vinasse

“…Similar values for concentration were obtained by Lima (2013), who found a nitrate concentration of 1,979.81 mg L -1 at a depth of 0.30 m, using the same soil as in this study. Tzanakakis et al (2011) evaluated the soil as a treatment system for agro-industrial effluent, and found that with increases in the volume of the effluents over the time of application, the potential risks of soil and groundwater contamination by nitrates reach dangerous levels. According to the authors, plant species with high rates of nitrogen absorption can reduce these risks, however, additional practices are necessary to control nitrate leaching and the accumulation of this ion in the soil, such as systems for the improvement of pre-application treatments and the dilution of effluents.…”

“…According to Rosolem et al (2010), the conversion of exchangeable potassium to non-exchangeable potassium can be quick, intensifying the losses due to leaching, as a result of processes to balance these ions in the soil. Sharma and Sharma (2013) found that sandy soils are more prone to potassium leaching, increasing the risk of the possible contamination of groundwater.…”