The effect of 0, 30, 90 and 270 kgha-1 rates of microelements on mustard was examined on a calcareous sandy soil in the region between the Rivers Danube and Tisza. The salts of the microelements were applied on a single occasion at the start of the experiment in spring 1995 in the form of Cr 2(SO4)3, K2Cr2O 7, CuSO4, Pb(NO3)2, Na 2SeO3 and ZnSO4. The 24 treatments (6 elements×4 application rates) in 3 replications gave a total of 72 plots, each measuring 7×5 = 35 m2. The location had the poor water regime typical of sandy soils, was prone to drought and was poorly supplied with NPK macronutri-ents. The ploughed layer contained 0.7-1.0% humus and 2-3% CaCO 3, and the groundwater was located at a depth of 5-10 m. The whole experiment was given 100 kgha-1 each of N, P2O5 and K2O active ingredients as basal fertilizer each year. The major results were as follows: - As a consequence of the dry spring and droughty summer, the yields were low: the seed yield had a dry mass of 0.8 tha -1 and the by-products (stem + pods) 4.5 tha-1. In the 9th year of the experiment the carry-over effects of Se, and to some extent the 90 and 270 tha-1 loads of Zn proved to be toxic. Se toxicity was manifested primarily in the generative phase, leading to an 85% drop in the seed yield compared with the control, while the mean plant height decreased from 96 to 53 cm and the by-product/main yield ratio increased from 5 to 12. The majority of the selenium applied as Na2SeO3 had already been leached into the subsoil as Ca selenate. - Lead could not be detected in the organs of mustard even on contaminated soil. The chromium concentration reached a level of 2-3 mgkg-1 in the by-products and 0.5 mgkg -1 in the seed in the Cr(VI) treatment. The copper concentration rose by 2-3 mgkg-1 at higher Cu rates, while the zinc concentration rose to a maximum of 20 and 33 mgkg-1 in the seed and stem, respectively. Selenium exhibited hyperaccumulation, with an increase of three orders of magnitude compared with the control. The mustard seed became unsuitable for human consumption and the stems for feeding purposes due to the extreme level of Se pollution. - The element uptake amounted to 8 g and 16 g Cr in the Cr(III) and Cr(VI) treatments, respectively, 33 g Cu, 197 g Zn and 949 g Se per hectare in the aboveground biomass. The Pb quantity was below the 1 gha-1 detection limit. A total of 16,675 years would be required for the elimination of the 270 kgha-1 rate of Cr in the Cr(VI) treatment, 8182 years for Cu, 1370 years for Zn and 285 years for Se. Phytoremediation does not appear to be a feasible solution for the cleansing of heavily polluted soils. - The specific element contents of 1 t seed + the relevant by-products exhibited extremely high values, exceeding the values considered acceptable by the Hungarian extension service 2-3-fold for P and K, nearly 4-fold for N and 8-fold for Ca and Mg, due to the very high by-product/main product ratio and to the concentration effect of drought on mineral element contents. These values cannot therefore be recommended for the estimation of the nutrient requirements of mustard, as they would be misleading. In reality, the nutrients not absorbed in the dry year can be utilized by the crop grown in the following year, thus reducing fertilizer requirements. In the case of combine harvesting the majority of the nutrients remain in the field and are ploughed in. On calcareous soils it is unnecessary to apply Ca or Mg, while K fertilizer is not required on heavier soils.
|Translated title of the contribution||Effect of microelement loads on mustard (Sinapis alba L.) grown on calcareous sandy soil|
|Number of pages||14|
|Journal||Agrokemia es Talajtan|
|Publication status||Published - Jun 1 2012|
ASJC Scopus subject areas
- Agronomy and Crop Science
- Soil Science