Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils

Distribution and availability of soil inorganic phosphorus fractions significantly influence plant phosphorus uptake and crop yield, particularly in alkaline soils, where phosphorus availability is often constrained by soil chemical properties. This study investigated the contribution of different p...

Full description

Saved in:
Bibliographic Details
Main Authors: Haifeng He, Xing Xu
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Agriculture
Subjects:
Online Access:https://www.mdpi.com/2077-0472/15/9/973
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849312936424636416
author Haifeng He
Xing Xu
author_facet Haifeng He
Xing Xu
author_sort Haifeng He
collection DOAJ
description Distribution and availability of soil inorganic phosphorus fractions significantly influence plant phosphorus uptake and crop yield, particularly in alkaline soils, where phosphorus availability is often constrained by soil chemical properties. This study investigated the contribution of different phosphorus fractions to phosphorus uptake and yield of alfalfa by applying four phosphorus addition levels: 0 kg/hm<sup>2</sup>, 50 kg/hm<sup>2</sup>, 100 kg/hm<sup>2</sup> and 150 kg/hm<sup>2</sup>, designated as P0, P50, P100, and P150, respectively, over two consecutive years. Correlation analysis and multiple linear regression analysis were employed to analyze the data. The results revealed that in alkaline soils, inorganic phosphorus fractions were dominated by aluminum-bound phosphate (Al-Pi) and decacalcium phosphate (Ca<sub>10</sub>-Pi), with storage contribution rates of 33.92% and 37.11%, respectively. In contrast, the cumulative storage contribution rates of dicalcium phosphate (Ca<sub>2</sub>-Pi), octocalcium phosphate (Ca<sub>8</sub>-Pi), iron-bound phosphorus (Fe-Pi) and occluded phosphorus (O-P) accounted for 28.97%. Although the storage contribution rate of Ca<sub>10</sub>-Pi was relatively low, its output contribution rate was high, rendering it easily absorbed and depleted by plants, thereby serving as an important source of soil phosphorus availability. Among these fractions, O-Pi was identified as the primary source of phosphorus for alfalfa, playing a critical role in P nutrition. Furthermore, Ca<sub>8</sub>-Pi exhibited a significant positive correlation with phosphorus uptake in alfalfa (R<sup>2</sup> = 0.98, <i>p</i> < 0.05) and was identified as a key factor influencing alfalfa yield, making it a reliable predictor for yield estimation.
format Article
id doaj-art-e98a7dffe86a40f6ad9c8371dfb31ff7
institution Kabale University
issn 2077-0472
language English
publishDate 2025-04-01
publisher MDPI AG
record_format Article
series Agriculture
spelling doaj-art-e98a7dffe86a40f6ad9c8371dfb31ff72025-08-20T03:52:56ZengMDPI AGAgriculture2077-04722025-04-0115997310.3390/agriculture15090973Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline SoilsHaifeng He0Xing Xu1College of Forestry and Prataculture, Ningxia University, Yinchuan 750021, ChinaCollege of Forestry and Prataculture, Ningxia University, Yinchuan 750021, ChinaDistribution and availability of soil inorganic phosphorus fractions significantly influence plant phosphorus uptake and crop yield, particularly in alkaline soils, where phosphorus availability is often constrained by soil chemical properties. This study investigated the contribution of different phosphorus fractions to phosphorus uptake and yield of alfalfa by applying four phosphorus addition levels: 0 kg/hm<sup>2</sup>, 50 kg/hm<sup>2</sup>, 100 kg/hm<sup>2</sup> and 150 kg/hm<sup>2</sup>, designated as P0, P50, P100, and P150, respectively, over two consecutive years. Correlation analysis and multiple linear regression analysis were employed to analyze the data. The results revealed that in alkaline soils, inorganic phosphorus fractions were dominated by aluminum-bound phosphate (Al-Pi) and decacalcium phosphate (Ca<sub>10</sub>-Pi), with storage contribution rates of 33.92% and 37.11%, respectively. In contrast, the cumulative storage contribution rates of dicalcium phosphate (Ca<sub>2</sub>-Pi), octocalcium phosphate (Ca<sub>8</sub>-Pi), iron-bound phosphorus (Fe-Pi) and occluded phosphorus (O-P) accounted for 28.97%. Although the storage contribution rate of Ca<sub>10</sub>-Pi was relatively low, its output contribution rate was high, rendering it easily absorbed and depleted by plants, thereby serving as an important source of soil phosphorus availability. Among these fractions, O-Pi was identified as the primary source of phosphorus for alfalfa, playing a critical role in P nutrition. Furthermore, Ca<sub>8</sub>-Pi exhibited a significant positive correlation with phosphorus uptake in alfalfa (R<sup>2</sup> = 0.98, <i>p</i> < 0.05) and was identified as a key factor influencing alfalfa yield, making it a reliable predictor for yield estimation.https://www.mdpi.com/2077-0472/15/9/973phosphorus componentsphosphorus effectivenessregression analysisphosphorus uptakealfalfayield prediction
spellingShingle Haifeng He
Xing Xu
Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
Agriculture
phosphorus components
phosphorus effectiveness
regression analysis
phosphorus uptake
alfalfa
yield prediction
title Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
title_full Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
title_fullStr Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
title_full_unstemmed Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
title_short Effects of Phosphorus Addition on Inorganic Phosphorus Fractions and Phosphorus Accumulation in Alfalfa in Alkaline Soils
title_sort effects of phosphorus addition on inorganic phosphorus fractions and phosphorus accumulation in alfalfa in alkaline soils
topic phosphorus components
phosphorus effectiveness
regression analysis
phosphorus uptake
alfalfa
yield prediction
url https://www.mdpi.com/2077-0472/15/9/973
work_keys_str_mv AT haifenghe effectsofphosphorusadditiononinorganicphosphorusfractionsandphosphorusaccumulationinalfalfainalkalinesoils
AT xingxu effectsofphosphorusadditiononinorganicphosphorusfractionsandphosphorusaccumulationinalfalfainalkalinesoils