Variations in fluorescence properties of humic acids from calcareous soils amended with different swine manures in a long-term soil experiment.

Molecular properties of soil humic acid (HA) can play an important role in the mechanisms regulating plant nutrient availability. This study explores how the structure of HA is altered by long-term treatment with different forms of swine manure and how these changes may influence nutrient availability. Liquid swine manure (LSM), solid swine manure (SSM), and swine manure compost (SMC) were applied to a calcareous soil over 17 years in a long-term soil fertility study.

Assessment of phosphorus status in a calcareous soil receiving long-term application of chemical fertilizer and different forms of swine manures.

The continuous use of organic inputs in crop production calls for an improved understanding of how these inputs might alter soil phosphorus (P). This study assessed how the continuous application of different forms of swine manure influences the mechanism of P transformation and release potential. Soil samples were collected from a clay loam soil receiving no P or 100 kg P ha applied as either chemical fertilizer (CHEM), swine liquid manure (SWL), composted swine manure (SWC), or solid swine manure (SWS) every other year for 16 years in a corn-soybean rotation.

Biotic and abiotic effects of soil organic matter on the phytoavailable phosphorus in soils: a review.

Soil organic matter (SOM) has a critical role in regulating soil phosphorus (P) dynamics and producing phytoavailable P. However, soil P dynamics are often explained mainly by the effects of soil pH, clay contents, and elemental compositions, such as calcium, iron, and aluminum. Therefore, a better understanding of the mechanisms of how SOM influences phytoavailable P in soils is required for establishing effective agricultural management for soil health and enhancement of soil fertility, especially P-use efficiency.

Application of biostimulant products and biological control agents in sustainable viticulture: A review.

Current and continuing climate change in the Anthropocene epoch requires sustainable agricultural practices. Additionally, due to changing consumer preferences, organic approaches to cultivation are gaining popularity. The global market for organic grapes, grape products, and wine is growing.

The effect of agroecosystem management on the distribution of C functional groups in soil organic matter: A review.

Unlabelled: To improve soil health and to aid in climate change mitigation, the quantity of soil organic matter (SOM) should be maintained or increased over the long run. In doing so, not only the total quantity of SOC but also the stability of SOC must be considered. Stability of SOC increases as a function of resistance to microbial decomposition or microbial substrate use efficiency through chemical, biological, and physical mechanisms including humification, hydrophobic moieties, molecular diversity, and formation of macroaggregates.

Phosphorus binding to soil organic matter via ternary complexes with calcium.

Soil organic matter (SOM) is known to exert a major control on the mobility and bioavailability of cationic nutrients. However, the role of SOM in the fate of anionic nutrients, especially phosphorus (P), is less well characterized. The objectives of this study were to (1) compare the formation of binary complexes of calcium (Ca) with humic acids (HA) extracted from two contrasting soils, and (2) determine if binary HA-Ca complexes could incorporate P by forming ternary HA-Ca-P complexes.

Speciation of Phosphorus from Agricultural Muck Soils to Stream and Lake Sediments.

The nature and management of agricultural soils can influence the forms of legacy P present in affected sediments; however, few studies have specifically characterized P in sediments affected by polder agriculture. In this study, the speciation of P as it flows from the muck soils of the Holland Marsh to the sediments of the West Holland River and Lake Simcoe, Ontario, Canada, was investigated. The distribution of P fractions and the characterization of organic P were analyzed by the sequential fractionation method and solution P nuclear magnetic resonance spectroscopy, respectively.

Preliminary validation of a sequential fractionation method to study phosphorus chemistry in a calcareous soil.

A sequential fractionation method proposed by Jiang and Gu (1989) distinguished three types of calcium phosphates (Ca-P) according to their different plant availabilities. Three extractants, NaHCO3, NH4Ac, and H2SO4 were used to extract Ca2-P, Ca8-P, and Ca10-P types, respectively, from soil. This sequential fractionation method was tested and modified for analyzing the P chemistry of a calcareous soil.