Organic Matter Relationship to Soil Nutrient Status and Aluminum Toxicity in Alfalfa¹

Abstract

The objective of this investigation was to evaluate in unaltered soils the relationship of organic matter (OM) to soil nutrient levels and aluminum (Al) toxicity to alfalfa. The Apand B21horizons from 12 agricultural soils were collected from throughout New Hampshire. The pH range of the soils was 4.91 to 6.60, exchangeable Al was 0.01 to 0.89 cmol (p+) kg−1, organic matter was 6.6 to 81.6 g/kg, and textures ranged from sandy to silt loams. Four kilograms of each soil were potted and seeded to alfalfa (Medicago sativaL.) in a greenhouse experiment. The level of soil OM was highly correlated with top dry weights of 3‐week old alfalfa and top and root dry weights of 9‐week old alfalfa. Increases in OM levels also resulted in corresponding increases in exchangeable soil calcium, magnesium, potassium, extractable phosphorus (Bray 1), total nitrogen, and cation exchange capacity (CEC). A significant amount of variation in the top dry weights of 3‐week old plants and in the top and root dryweights of 9‐week old plants was accounted for by taking into consideration the interaction of Al and organic matter. With the use of three‐dimensional computer plotting programs, the critical Al level of alfalfa was correlated with soil OM levels (r=0.883). An incremental increase of 1% in soil OM on a dry‐weight basis (starting from about zero) increased critical Al levels by 0.3 cmol (p+) kg−1

Influence of effective microorganisms and green manure on soil properties and productivity of pearl millet and alfalfa grown on sandy loam in Saudi Arabia

“…Incorporation of green manure wit h soil showed a tendency of immobilizing available P (Somado et al, 2007). Green manure increase the concentration of K, Mn, Fe, either by increasing their solubility from soil insoluble mineral fraction or releasing these nutrients from t he decomposition of organic matter (Kapland and Estes, 1985;Mosavi et al, 2009). Karami et al (2012) found that, soil Mn concentration was increased when applying different organic matter sources.…”

How soil carbon fractions relate to soil properties and crop yields in dryland cropping systems?

“…Soil organic matter is the main source of micronutrients to plants, as micronutrient fertilizers are not usually applied to crops (Johnson, 1991). Kapland and Estos (1985) reported that SOC correlated to Ca, Mg, K, Bray‐1 P, and Al concentrations. Similarly, van Es and Karlen (2019) found that PCM related to soil P, K, Mg, and Mn concentrations.…”

Recomendação alternativa de calcário para solos altamente tamponados do extremo sul do Brasil

“…Nesse valor de pH, nenhum solo apresentou Al 3+ superior a 1,5cmol c kg -1 , mesmo aqueles que originalmente apresentavam mais de 6,0cmol c kg -1 (tabela 2). Nesse trabalho, os solos com maior tamponamento possuem também altos teores de matéria orgânica, o que minimiza a toxicidade do Al aos vegetais (KAPLAND & ESTES, 1985). Por isso, é importante preservar ao máximo a M.O.…”