Removal of Lithium Citrate from H3A for Determination of Plant Available P

• 作者: Douglas R. Smith Elizabeth B. Haney Michael J. White Richard L. Haney
• 来源期刊: 土壤科学期刊(英文)
• 学科: 医学
• 关键词: PHOSPHATE Soil EXTRACTION LITHIUM CITRATE
• 年，卷（期）: 2017,（11）
• 页码范围: 301-314
• 页数: 14页
• 分类号: R73

摘要

The soil extractant, H3A, has undergone several iterations to extract calcium (Ca), iron (Fe), aluminum (Al), potassium (K), phosphorus (P), ammonium (NH4-N) and nitrate (NO3-N) under ambient soil conditions. Few soil extractants currently used by commercial and university soil testing laboratories can perform multi-nutrient extraction without over- or under-estimating at least one nutrient. Soil pH and plant root exudates have a strong influence on nutrient availability and H3A was developed to mimic soil conditions. Lithium citrate was previously used in the H3A formulation, but resulted in a cloudy supernatant in some samples, complicating laboratory analyses. In this study, we removed lithium citrate and compared the nutrients extracted from the modified (H3A-4) to the established (H3A-3) solutions. We found that the new extractant, H3A-4, produced a clear supernatant even in soils with low pH and high iron and aluminum concentrations. H3A-4 accurately predicts plant available nutrients and is a viable choice for commercial and laboratory settings due to its ease of use.