Interactions between the elements potassium, boron and strontium were analysed in alfalfa grown on a pseudomyceliar (calcareous) chernozem soil at the Experimental Station of the institute in Nagyhörcsök (Mezoföld) between 1991 and 1994. Before the alfalfa was sown, a basal dose of 400 kg P2O5ha-1 was applied in the form of superphosphate. The K levels were adjusted with repeated doses of 0, 1000 and 2000 kgha-1 K2O, the B levels with repeated doses of 0, 20, 40 and 60 kgha-1 B and the Sr levels with a rate of 67 kgha -1 Sr. The fertilizers were applied in the form of 60% potassium chloride, 11% borax and 33% SrCl2×6H2O. The three K treatments formed the main plots, the four B treatments the sub-plots and the two Sr treatments the sub-subplots, giving a total of 24 treatments×3 replications = 72 plots in a split-plot design. When the experiment was set up in autumn 1987 the ploughed layer contained 5% CaCO3, 3% humus and 20% clay, with pH(H2O) 7.8, pH(KCl) 7.3, and nutrient contents (mgkg-1) of 180-200 AL-K2O, 100-120 AL-P2O 5, 110-150 KCl-soluble Mg, 60-80 KCl+EDTA-soluble Mn, 1-2 Cu and Zn, and 0.7 B. The soil had satisfactory supplies of K, Ca and Mg, moderate supplies of N and P and poor supplies of Zn and Cu. The groundwater was located at a depth of 13-15 m and the area was prone to drought. The mean temperature averaged 11°C and the annual rainfall sum ranged from 400 to 600 mm, with uneven distribution. The main conclusions were as follows: - On this calcareous loam soil, which was satisfactorily supplied with both potassium and boron, fertilizer effects were not detected in the yield. Even the extremely high, repeated rates of 2000 kgha-1 K2O and 60 kgha-1 B did not lead to yield depression. The AL-K2O content of the soil rose from 191 in the control to 515 mgkg-1 at the highest rate, and the hot water-soluble B content from 0.7 to 5.1 mgkg-1. - The B content of alfalfa rose in the same treatments from 30-50 to 50-120 mg kg -1. The K concentration of the hay increased parallel with K fertilization, while that of Na, Mg, Ca and Cu declined. The Cu content of the hay was also significantly reduced by B fertilization, thus aggravating the latent Cu deficiency and resulting in Cu contents of around 3 mgkg-1 in the hay. - Two-year-old alfalfa had the highest contents of the macronutrients N, K, Ca, Mg, S and P and also gave the highest hay yield. It consequently exhibited the highest level of nutrient uptake, with per hectare quantities of 319 kg N, 176 kg K (211 kg K2O), 184 kg Ca, 31 kg S, 28 kg Mg and 22 kg P (50 kg P2O5). - A total of 26.4 tha-1 hay was produced over the 4 years, with the incorporation of 756 kg N, 654 kg K2O and 158 kg P2O5. Alfalfa production results in a rapid depletion of the soil, particularly in terms of potassium. In soils poor in lime, the calcium also becomes depleted, as the Ca uptake remains at a similar level. Most of the nitrogen absorbed, however, originates from the atmosphere. The nitrogen-rich root residues remaining in the soil improve the N-supplying ability of the soil, reducing the N fertilizer requirements of the succeeding crop. - On this soil, the mean specific element requirements for the formation of 1 t hay between 1991 and 1994 were 20-40 kg N, 18-22 kg K and Ca, 3-4 kg Mg and S, and 2-3 kg P (5-7 kg P2O 5). These data could serve as guidelines for calculating the K, Ca, Mg, P and S requirements of the planned yield. The deviations in the specific microelement contents were as follows: 400-500 g Na, 80-120 g Fe and Sr, 40-60 g Mn, 20- 50 kg Al and B, 12-16 g Zn, 8-10 g Ba, 5-20 g Cu and 0.3-1.4 g Ni. The specific Zn and Cu parameters reflect the poor supply levels of the location, being below the optimum.
|Translated title of the contribution||Analysis of interactions between potassium, boron and strontium in alfalfa|
|Number of pages||18|
|Journal||Agrokemia es Talajtan|
|Publication status||Published - Jun 1 2012|
ASJC Scopus subject areas
- Agronomy and Crop Science
- Soil Science