Kuzin Andrei I, Kashirskaya Natalia Ya, Kochkina Anna M, Kushner Alexey V
I.V. Michurin Federal Scientific Centre, 393774 Michurinsk, Russia.
Department of Horticulture, Michurinsk State Agrarian University, 393760 Michurinsk, Russia.
Plants (Basel). 2020 Oct 15;9(10):1366. doi: 10.3390/plants9101366.
The proper use of potassium fertilizer can stimulate a significant yield increase. However, the application of excessively high rates of potassium can reduce the availability of soil calcium for apple trees. The potassium fertigation rate must meet the apple tree's requirements so that the applied fertilizers can be absorbed by the roots as much as possible. Crop load in apple orchards sometimes varies significantly in different years. The potassium content in apple fruits is relatively high, and the maximum requirement for this nutrient occurs when fruits grow and ripen. Different crop loads at that time mean the various demands of trees and need for changing application rates for this nutrient. The investigation was carried out in the experimental orchard of I.V. Michurin Federal Scientific Centre (Michurinsk, Russia) in 2016 and 2017 (52.885131, 40.465613). We studied seasonal changes of potassium and calcium contents in soil, fruits, and leaves and their relationship with yield during the research. We paid much attention to the potassium rate shift on its content in leaves and fruits and cultivars "Lobo" and "Zhigulevskoye" yield. If the potassium application rate changes according to the actual crop load, it stimulates the yield growth or (if the crop load was relatively low) the reduction of the rate did not lower the productivity. Moreover, we studied the relationship between potassium and calcium nutrition. The decrease in potassium fertigation rate increased the availability of soil calcium. It was the reason for fruit calcium concentration enlargement and mitigation of the K/Ca ratio. We also specified some parameters for soil-leaf diagnosis for potassium nutrition during the growing season.
合理使用钾肥可显著提高产量。然而，施用过高剂量的钾会降低苹果树对土壤钙的吸收。钾肥的滴灌速率必须满足苹果树的需求，以便使施用的肥料尽可能多地被根系吸收。苹果园的作物负载量在不同年份有时会有显著差异。苹果果实中的钾含量相对较高，在果实生长和成熟时对这种养分的需求最大。此时不同的作物负载量意味着树木的不同需求以及对该养分施用量变化的需要。该研究于2016年和2017年在俄罗斯米丘林斯克的I.V. 米丘林联邦科学中心的试验果园（52.885131, 40.465613）进行。在研究过程中，我们研究了土壤、果实和叶片中钾和钙含量的季节性变化及其与产量的关系。我们特别关注钾肥施用量变化对叶片和果实中钾含量以及“洛博”和“日古列夫斯科耶”品种产量的影响。如果根据实际作物负载量改变钾肥施用量，会促进产量增长，或者（如果作物负载量相对较低）减少施用量也不会降低生产力。此外，我们研究了钾和钙营养之间的关系。降低钾肥滴灌速率会增加土壤钙的有效性。这就是果实钙浓度增加和钾/钙比降低的原因。我们还确定了生长季节土壤 - 叶片钾营养诊断的一些参数。
