THE EFFECT OF WEATHER CONDITIONS ON THE YIELD AND MACRONUTRIENT CONTENT IN THE ABOVEGROUND BIOMASS OF WHITE MUSTARD (Sinapis alba L.) CULTIVATED AS STUBBLE CATCH CROP
Background. White mustard is a valuable plant as a stubble catch crop due to a relatively cheap seed material, tolerance to delayed sowing date and high yield stability. The aim of this research was determination of thermal and rainfall requirements of white mustard cultivated as stubble catch crop in conditions of sandy loam soil, of the very good rye complex.
Material and methods. The field studies were carried out at the Experimental Station in Mochełek, near Bydgoszcz in the years 2010–2015. White mustard cv. Bamberka was sown on 08–18 August, on lessive soil, belonging to the very good rye complex. The soil was characterized by a very high content of available phosphorus and magnesium, as well as a high content of potassium. The soil reaction in 1M of KCl was 6.48.
Results. Weather conditions played an important role in the formation of white mustard yield and of the content of nitrogen, phosphorus and potassium in the aboveground biomass. Over the years with moderately high rainfall, a greater plant density was obtained as well as longer stems in white mustard, which resulted in this plant’s yield. The highest dry matter yields (1.77–2.08 Mg·ha-1) were harvested over the years in which the total rainfall in the period from July to October was 218.3–250.4 mm, from which 62-80% occurred in July and August. Poor production results were obtained not only in the years with rainfall deficit in July and August, but also under conditions of excessive rainfall in these months.
Conclusion. Under conditions of lessive soil, belonging to a very good rye complex, an optimal rainfall for white mustard cultivated as stubble catch crop, without fertilization, was 244 mm in the period July – October, from which 172 mm occurred in the period July–August.