Interannual dynamics of available potassium in a long-term fertilization experiment

Abstract

Dynamics of the plant-available potassium (K) has been studied in polyfactorial long-term fertilization experiments since 1980. The fertilization scheme includes 10 combinations of K muriate and farmyard manure application rates (annually 0-230 kg K/ha). at medium treatment (annually 153 kg K/ha), the K balance within an 8-year crop rotation reflected crop specific K application rates with positive annual balances in years of growing silage maize and sugar beet (high K input), and negative in two years of growing alfalfa. available K clearly corresponded to the dynamics of the K balance, with statistically significant fluctuations from 88 to 149 mg K/kg within one crop rotation cycle. Periodic fluctuations of available K induced by crop rotation were observed also in non-fertilized treatments. The variability of available K contents was influenced primarily by crop plants and experimental unexplained factors; interannual weather fluctuations and field differences were of low significance. in the paper, the importance of interannual K dynamics for the construction of correct long-term time trends is shown and discussed.

Effect of liming on the change of some agrochemical soil properties in a long-term fertilization experiment

“…Long-term experiments point to a complex of direct and indirect changes in physicochemical and biological soil properties affected by the application of organic and mineral fertilizers or no fertilizers at all. Fertilization affects soil properties essential for its agricultural quality and ecological balance: the content and transformations of organic carbon (Kubát et al 2006), acidification and soil reaction (Debreczeni and Kismanyoky 2005), nutrients contents as well as their availability to plants (Madaras and Lipavský 2009). The main reasons of unfavourable changes in soil and other components of agroecosystems are a lack or low organic fertilization, nutrients-unbalanced mineral fertilization, high doses of nitrogen, skipping liming, unbalanced fertilizer doses as compared with the plant fertilization needs.…”

Mechanical weeding of Rumex obtusifolius L. under different N, P and K availabilities in permanent grassland

“…The concentrations of plant-available (Mehlich III) P and K were 152 mg/kg and 267 mg/kg in the upper 10 cm soil layer, respectively. These values are considered to be optimal for crops with a high P and K demand (Kulhánek et al 2009, Madaras andLipavský 2009), and for highly productive grasslands (Hrevušová et al 2009). The seedlings of R. obtusifolius were not counted separately as it was difficult to distinguish between seedlings and plants regenerating from underground organs.…”

Soil Enzyme Activities, Microbial Diversity and Available Nutrients Status of an Alfisol under Long Term Fertilization

“…Long-term experiments point to a complex of direct and indirect changes in physicochemical and biological soil properties affected by the application of organic and mineral fertilizers or no fertilizers at all. Fertilization affects soil properties essential for its agricultural quality and ecological balance: the content and transformations of organic carbon (Kubat et al, 2006), acidification and soil reaction (Debreczeni and Kismanyoky, 2005) nutrients contents as well as their availability to plants (Madaras and Lipavsky, 2009). …”