Phosphorus fractions depletion in the rhizosphere of young and adult maize and oilseed rape plants
Phosphorus fractions depletion in the rhizosphere of young and adult maize and oilseed rape plants
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DOI：
10.4067/s0718-95162017000300020
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发表时间：
2017-09-01
影响因子：
3.9
通讯作者：
Claassen, Norbert
中科院分区：
文献类型：
--
作者：
Cabeza, Ricardo A.;Myint, Kyi;Claassen, Norbert
在碱性土壤中，大部分的P是酸溶性的，我们假设，酸化根际的物种，如油菜，更有效地利用土壤P比例如玉米。在田间试验中，成年玉米植株每单位根吸收的磷比幼株多。在这里，我们假设，老厂访问P馏分，年轻的植物不能。因此，本研究的目的是研究生长在酸性桑迪和中性壤土中的玉米和油菜所利用的磷组分以及植物年龄对其的影响。为了获得根际土壤，将一部分根浓缩以在由细尼龙网覆盖的平坦土壤表面上形成根垫。将网另一侧的土壤切成薄片，得到距根表面不同距离的根际土壤。我们研究了玉米和油菜在三个生长阶段所使用的P组分，通过测量根际三种无机（P-I）和两种有机（P-O）P组分的消耗。油菜对两种土壤中的磷-氧组分均无影响，而玉米只对酸性土壤中的磷-氧组分有影响。两种土壤中的两个物种都只耗尽了碱溶性P-1部分。消耗程度在12- 26%之间。油菜和玉米都不消耗酸溶性P-1。株龄对P组分的耗竭或耗竭程度没有影响。
In alkaline soils, where most of the P is acid soluble, we hypothesize that species that acidify the rhizosphere such as oilseed rape, are more efficient to use soil P than for example maize. In field experiments, adult maize plants extracted more P per unit of root than young plants. Here we hypothesize that older plants access P fractions that younger plants were not able to. Thus, the aim of this research was to study the P fractions used by maize and oilseed rape growing in an acid sandy and a neutral loamy soil and how plant age might affect it. A special pot system was developed in which P uptake by the plants came from roots that grew freely in soil. To obtain rhizosphere soil, a portion of the roots was concentrated to form a root mat on a planar soil surface covered by a fine nylon mesh. Cutting the soil on the other side of the mesh into slices gave rhizosphere soil at different distances from the root surface. We examined the P fractions used by maize and oilseed rape at three growth stages by measuring the depletion of three inorganic (P-i) and two organic (P-o) P fractions in the rhizosphere. Oilseed rape did not affect the P-o fractions in any of the two soils, and maize only in the acid soil. Both species in both soils depleted only the alkali soluble P-i fraction. The degree of depletion was between 12-26 %. The acid soluble P-i was not depleted by neither oilseed rape nor maize. Plant age had no effect on P fraction depleted or on the degree of depletion.