Impact of soil organic matter on soil properties—a review with emphasis on Australian soils

Abstract

A review has been undertaken into how soil organic matter (SOM) affects a range of soil properties that are important for the productive capacity of soils. The potential effect of varying the amount of SOM in soil on a range of individual soil properties was investigated using a literature search of published information largely from Australia, but also including relevant information from overseas. The soil properties considered included aggregate stability, bulk density, water-holding capacity, soil erodibility, soil colour, soil strength, compaction characteristics, friability, nutrient cycling, cation exchange capacity, soil acidity and buffering capacity, capacity to form ligands and complexes, salinity, and the interaction of SOM with soil biology. Increases in SOM have the capacity to have strong influence only the physical properties of the surface soils, perhaps only the top 10 cm, or the top 20 cm at most. This limits the capacity of SOM to influence soil productivity. Even so, the top 20 cm is a critical zone for the soil. It is where seeds are sown, germinate and emerge. It is where a large proportion of plant materials are added to the soil for decomposition and recycling of nutrients and where rainfall either enters the soil or runs off. Therefore, the potential to improve soil condition in the top 0–20 cm is still critical for plant productivity. The SOM through nutrient cycling such as mineralisation of organic nitrogen to nitrate can have an influence on the soil profile.

Increasing Soil Organic Matter Enhances Inherent Soil Productivity while Offsetting Fertilization Effect under a Rice Cropping System

“…They argued that the labile P was reduced, arising from the mineralization of organic P and the subsequent transformation of surplus inorganic P to unavailable forms associated with calcium (Ca) in temperate soils or iron (Fe) and aluminum (Al) in tropical soils. SOM could prevent P being fixed into unavailable forms, keeping it in the form which remained in the available pool for plants, even if this organic P needed to be mineralized before it became immediately available to plants [4]. In addition to the effect on N and P, SOM contains both anion and cation exchange sites that might be able to hold readily available K for crops [3].…”

“…SOM can contribute to soil quality and subsequent crop yield in a number of ways, for instance, nutrient cycling and supplying during its decomposition, aggregate stability and soil porosity, water-holding capacity especially available water, and cation exchange capacity [3,4]. On the other hand, the crop yield is a consequence of interactions among intrinsic soil properties, external climatic conditions, and management strategies including fertilization, irrigation, and tillage.…”

“…In recent decades, SOM accumulation, and hence soil organic carbon (SOC) sequestration, has been given much attention as a climate change mitigation option on global and regional scales to address the rapidly increasing CO 2 in the atmosphere [2]. On the other hand, SOM accumulation is an important option, not only to mitigate climate change, but also to improve soil quality because of its extensive impacts on soil physical, chemical, and biological properties [3,4]. In previous studies, changes of SOM in croplands have been quantified using different scales in China [5,6], however, the potential influence of the SOM change on crop yields and input requirements in the farmland systems is unclear because great uncertainty about the relationship between SOM and crop yield still remains.…”

Effect of Organic Manures on Nutrient Uptake and Seed Quality of Sesame

“…Organic materials are a major source of organic matter and plant nutrients. Incorporating organic materials into soil results in improved soil physical attributes namely: soil structure, soil aggregate stability, water holding capacity, soil drainage, soil aeration and root penetration and soil chemical attributes namely: soil nutrient content and composition and soil pH (Craswell et al, 2001;Murphy., 2015). Application of organic manures on sesame in form of crop residues and animal manure would most likely improve its yields and seed quality (Anyanga et al, 2001;Morris, 2002;Bedigian, 2003).…”

Influencia del biocarbón aplicado al suelo sobre atributos de rendimiento y calidad de avena forrajera

“…Algunas prácticas pueden mejorar la productividad agrícola; por ejemplo, la incorporación de materiales orgánicos al suelo (Murphy, 2015;Putwattana et al, 2015;Woldetsadik et al, 2016;Xie et al, 2017). La aplicación de biocarbón (BC) ha sido propuesta como una opción de gran interés debido a sus benef icios en el suelo y cultivos Plaza et al, 2016;Trupiano et al, 2017).…”