Evaluating the effects of different nutrient management strategies on apple (malus pumila) in intensive orchards of Kazakhstan. Results from a 4-year study

Abstract

This article presents the findings of a four-year study in intensive apple orchards in southern Kazakhstan, evaluating different nutrient management strategies on apple trees (Malus pumila). The research aimed to assess the impact of nutrition plans on tree growth, productivity, and fruit quality, considering the region's unique soil and climate. The experiment, established in 2014, covered 1.5 hectares and consisted of Jeromini apple trees grafted onto M9 rootstock. Three treatment groups were established: a control group with no additional nutrition, a group with nutrition based on a generally accepted program, and a group with nutrition tailored to the apple tree's needs with fertigation. Phenological and biometric observations were conducted regularly from 2019 to 2022 to monitor tree performance. Soil and leaf samples were analyzed for nutrient content, and soil properties like pH and salinity were assessed. Statistical analysis was used to identify significant differences among the treatment groups. The research was conducted in intensive apple orchards located in the Turkestan region, known for its grey-brown soil. The climate in the study area was characterized as continental, with hot and dry summers and limited precipitation. Soil samples were analyzed for agrophysical and agrochemical properties, including nutrient levels and trace elements. The results showed that the control group had a decreasing trend in yield, while both the generally accepted program and the tailored nutrition program showed increasing trends in yield, with the latter showing a decrease in 2022. Over the fouryear period, the fruits from the control group exhibited reduced commercial qualities. Our program demonstrated similar sweetness and superior shape and yield compared to the conventional method. However, the storage quality of apples in our program was lower. Nevertheless, considering its positive impact on soil fertility and cost-effectiveness, our program appears to be an optimal choice. The findings of this study provide valuable insights into the effects of different nutrient management strategies on the growth, health, and productivity of apple trees in a garden setting. This information can benefit orchard growers and researchers seeking to optimize nutrient management practices for apple trees. The study also highlights the importance of considering various factors, such as orchard characteristics and environmental conditions, when designing nutrient management strategies for apple orchards.