Фактори формування поживного режиму ґрунту в плодових насадженнях півдня України

Abstract

Показано, що рівень нагромадження поживних речовин у чорноземі південному та інтенсивність їх поглинання зернятковими культурами залежать від зміни вмісту елементів живлення унаслідок застосування мінеральних добрив, а також вологості й температури ґрунту.

Показано, что уровень накопления питательных веществ в черноземе южном и интенсивность их поглощения семечковыми культурами зависят от изменений содержания элементов питания вследствие применения удобрений, а также влажности и температуры почвы.

The goal of the said research was determination of main factors of southern chernozem nutrition regime formation in orchards and their impact on the processes of nutrition substances absorption by pome crop trees in the conditions of south of Ukraine. The research was held on the basis of field experiments that studied systems of mineral nutrition of pears and apples, taking the features of soil conditions of the South of Ukraine, age periods, and technology of growth in the lands of Melitopol fruit growing research station named after M.F. Sidorenko of IH of NAAS into consideration. Schemes of the experiments reckon for the study the effect of application of different doses, methods, and ratios of nitrogen, phosphorus, and potassium in orchards on 4 pear varieties (Vesilna, Pektoral, IzuminkaKrimu, Conference) and 2 apple varieties (Idared and Florina). As a result of the research of studying the influence of long-term mineral fertilizer application (2004-2014) upon transformation of southern chernozem nutrition regime in pome crop orchards, it has been determined that dynamics of nitrogen, phosphorus, and potassium contents changes during vegetation period are caused by the dose of fertilizers as well as hydrothermal conditions of the soil, in particular soil humidity and temperature. A dose of particular type of mineral fertilizer has the highest impact upon the dynamics of accumulation of main macroelements in the soil. However, the impact of hydrothermal conditions of the soil is also statistically reliable for nitrogen and phosphorus during the whole vegetation period, for potassium – in the middle and the end of vegetation. Besides, as a result of studying the influence of application of nitrogen only, as well as in different combinations with phosphorus and potassium, in 90-95% of cases the fact of formation of “extra nitrogen” has been determined, its amount varying from 7.3 to 44.6 mg/kg of the soil, depending on doses and terms of fertilization. One-term nitrogen application had the biggest nitrogen mobilizing effect while divided (especially in combination with phosphorus and potassium) decreased its amount, being a positive fact in the reduction of non production spending of nitrogen. As a result of mathematical analysis of the data it has been determined that the biggest effect on nitrates contents in the soil of pear orchards is caused by factor “fertilizer dose” (55-71%) and “soil temperature” (21-35%); at the same time concentration of ammonium nitrogen was more influenced by the terms of observation. Changes in the contents of exchange forms of potassium were the least influenced by said factors. Factors that determine the intensity of absorption of nutrition substances by fruit tees were also detected. It was pointed out that the levels of nutrition substances accumulation in southern chernozem in pome crop orchards, as well as the intensity of their absorption by apple and pear trees depend on contents changes of nutrition elements because of fertilization, and also on soil humidity and temperature. Biggest intake of nitrogen, phosphorus, and potassium by the plants was observed during the humidity of 70-80% of field capacity, temperature of 22–26 0С, and the contents of N-NO3in the soil – 14,5–21,7 mg/kg, Р2О5 – 3,9÷5,0 mg/100 g, К2О - 29,4–37,2 mg/100 g. However, maximum soil temperature in combination with low humidity (draught conditions) even in case of relatively high amounts of mobile forms of macroelements delay the absorption of nutrition elements by fruit crops.