Different forms of soil potassium as affected by the age of pistachio (Pistacia vera L.) trees in Rafsanjan, Iran
Different forms of soil potassium as affected by the age of pistachio (Pistacia vera L.) trees in Rafsanjan, Iran
复制标题
DOI：
10.1016/j.geoderma.2009.12.013
复制
发表时间：
2010-03-15
期刊：
影响因子：
6.1
通讯作者：
Kalbasi, Mahmoud
中科院分区：
文献类型：
--
作者：
Hosseinifard, Seyed Javad;Khademi, Hossein;Kalbasi, Mahmoud
阿月浑子是一种主要作物，占伊朗农产品出口的相当大一部分。尽管钾在阿月浑子生产中的重要性，但目前还没有关于土壤中不同形式的钾随阿月浑子树龄变化的信息。本研究的目的是评价不同树龄阿月浑子园土壤中不同形态钾的状况。在伊朗拉夫桑贾地区的三个不同地区选择了10年、20年和40年三个不同树龄的阿月浑子果园。每个阿月浑子果园附近的一块处女地也被选为对照。在每个果园中挖掘三个土壤剖面，以及从对照原始地块中挖掘三个土壤剖面，以采样其遗传层。水溶性，交换性，非交换性和结构钾提取和测定。结果表明，未开垦地的可溶性钾含量高于不同树龄阿月浑子园。在土壤中最初丰富的交换性钾，阿月浑子树生长超过10，20，或40年显着减少交换性钾的8.4%，46.3%和43.6%，分别。在土壤交换性钾含量较低的其他两个地区，交换性钾含量平均减少2 ~ 20%。非交换性钾组分显着低于10，20，40岁的阿月浑子果园相比，在未开垦的对照土壤，特别是在土壤交换性钾主要是低的地区。非交换性钾的最高降幅为50%的40岁的阿月浑子果园在该地区的交换性钾是最低的土壤。此外，非交换性钾的减少是最高的根区相比，其他土层。这些研究结果表明，植物的钾吸收，阿月浑子树年龄，和交换性钾的主要地位是影响阿月浑子果园土壤中含钾矿物钾耗竭的重要因素。这表明在交换性钾含量低于200 mg kg（-1）的老阿月浑子果园中可能需要施用钾肥。(C)2009爱思唯尔有限公司版权所有。
Pistachio is a major crop that accounts for a considerable portion of Iranian agricultural exports. Despite the importance of potassium in pistachio production, no information is currently available on the changes of different forms of K in soil with pistachio tree age. The objective of the present study is to evaluate the status of different forms of soil K in pistachio orchards with trees of different ages. Pistachio orchards of three different ages of 10, 20, and 40 years old were selected in three different regions in Rafsanjan area, Iran. A piece of virgin land adjacent to each pistachio orchard was also selected as control. Three soil profiles were excavated in each orchard as well as three from the control virgin plots to sample their genetic horizons. Water soluble, exchangeable, nonexchangeable, and structural K were extracted and determined. Results showed that the amounts of soluble K in the virgin land were higher than those in the pistachio orchards with different tree ages. In soils initially rich in exchangeable K, growth of pistachio trees over 10, 20, or 40 years significantly reduced exchangeable K by 8.4, 46.3 and 43.6%, respectively. For the other two regions where soil exchangeable K was primarily lower, average reduction in exchangeable K was 2 to 20%. The nonexchangeable K fraction was significantly lower in the 10, 20, and 40-year-old pistachio orchards as compared to that in the uncultivated control soil, especially in regions where soil exchangeable K was primarily low. The highest reduction in nonexchangeable K was 50% for the 40-year-old pistachio orchards in the region where exchangeable K was lowest in the soil. Moreover, the reduction in nonexchangeable K was highest in the root zone as compared to the other soil layers. These findings suggest that uptake of potassium by plants, pistachio tree age, and primary status of exchangeable K are important factors affecting K depletion from K bearing minerals in soils under pistachio orchards. This indicates the possible need to apply K fertilizers to old pistachio orchards where exchangeable K might be lower than 200 mg kg(-1). (C) 2009 Elsevier B.V. All rights reserved.