Effect Of Water And Potassium Interaction On Soil Potassium Content And Maize Growth

Water and potassium are two essential factors affected maize growth, and play a crucial role in yield increase and quality improvement of agricultural products. Calcareous cinnamon soil belongs to the zonal soil type, and is an important agricultural soil in Shanxi province. There are few reports on the effect of water and potassium interaction on calcareous cinnamon soil. In this paper, based on the management need of water and potassium resource of calcareous cinnamon soil, pot-experiment on water and potassium interaction was conducted with the randomized block design and five replicas to explore the response of potassium content to water and potassium interaction, and to study the effect of maize growth as well as water use efficiency and agronomic efficiency of potassium. This study will provide a scientific base on the management of water and potassium resource. The main results obtained are summarized as follows:1. The response of potassium content to water and potassium interactionThe soil culture experiment results indicated that the soil moisture influenced the soil potassium.Compare with the test soil before, the content of soil water-soluble potassium, exchangeable potassium and non-exchangeable potassium of without potassium application treatment (Ko) after the test significantly decreased by 37.7%,43.5% and 2.6%, respectively. And the content of soil water-soluble potassium, exchangeable potassium and non-exchangeable potassium had an increased tendency with the increased rate of irrigation (W3>W2>W1). These indicated that soil moisture increase helped to increase the content of soil potassium under the condition of without potassium application.2. The response of maize growth to different water and potassium treatmentThe results indicated that under the condition (field moisture capacity by 60-80% and potash applied by 0-0.2g K2O/kg soil), maize growth were affected by soil water and potassium rate, and the growth parameter such as plant height, stem diameter, leaf area, fresh weight, dry weight and potassium uptake had an increased tendency with the increase of irrigation rate and potash application rate. Under the W1 condition (field moisture capacity by 60%), above parameters had an increasing tendency with the increase of potash application rate, and K3 (0.2g K2O/kg soil) treatment was higher. Under the condition of without potash application (Ko), parameters above were also increased with the irrigation rate increased. These indicated that during crop growth, certain strategy was taken on the management process of irrigation and potash application. When the water was shortage, increasing the rate of potash application may help to promote the maize growth, thus the effect of water obtained by fertilizer application; and when potassium was shortage, increasing the rate of irrigation may also had a help to maize growth, thus the effect of fertilizer application was obtained by irrigation.3. The response of efficiency of water and potassium use to different water and potassium treatmentThe efficiency of water use for maize increased with the rate of irrigation and potash application under the certain condition, but the agronomic efficiency of potash application decreased with the rate of potash application. Therefore, maize growth, water use efficiency and agronomy efficiency of potash use were considered, field moisture capacity by 70% and potash application by 0.10g K2O/kg soil may provide the right condition for maize growth.4. Evaluation of the availability of soil potassiumSoil culture experiment was conducted that the available potassium of the fresh soil was more effective and convenient to the in-situ soil within a certain moisture content. The determination of soil available potassium content by air dried soil is less than that of fresh soil. And the correlation between the determination of soil available potassium content by fresh soil and maize dried weight are better than that by the air dried soil. These indicated that supply capacity of soil potassium by the determination of soil available potassium content by air dried soil with conventional method were limitation to some extend.