Increasing crop yields per acre to meet future food and fibre demand increases the importance of depleting soil nutrients and replenished soil fertility through effective nutrient management practices. Significant advances in improving nutrient use efficiency in planting production require better estimates of nutrient content in plants in the root zone, improving crop response to these nutrients, and nutrient uptake. Therefore, this article is mainly based to educate people about soil fertility management practices for improved production of food quality and quantity.
Soil fertility management in different areas and conditions
As a world-class area suitable for agricultural production is currently under cultivation, future demand for food and fibre must be met by increasing crop yields per unit of land. More than 50% of the world’s landmass has been degraded, and in some areas close to 70% of the land is under threat due to accelerated urbanisation, and industrialisation. Only 11% of the world’s land is arable land from Class I to III, which would support a 50% increase in agricultural production in 2050 to feed about 9.5 billion people.
Effects of degraded land on soil fertility
Effects of land degradation (such as erosion) onsite and off-site (sediment construction) are greatly important for soil fertility. The effects of land degradation on agricultural productivity include physical processes (scaling, compression, erosion, and desertification), chemical (acidity, leaching, salinity, and fertility deficiencies), and biological (oxidation/carbon loss, and microbial biodiversity). Out-of-site effects are related to the erosion of environmental water nutrients, groundwater, and trace gases (carbon dioxide, methane, nitrous oxide, and nitrogen oxides).
Soil fertility management in relation to soil properties
Many of the biological, chemical, and physical properties of soil that are affected by soil degradation processes at the site also affect soil fertility and nutrient availability for plants. It is important to understand these processes and interactions to improve the availability of plant nutrients and reduce nutrient losses in the environment. When plants are removed from the field or soil sediment is moved, the nutrients in the soil are depleted. Soil supply of native nutrients depends on the ability of the soil to prevent nutrient loss through crop extraction.
Therefore, to improve the nutrient supply of crops and reduce the environmental hazards of nutrient use, it is important to understand the interactions and processes of soil, soil nutrients (soil fertility) and to provide adequate soil nutrient supply. Effective management of organic and inorganic nutrients (nutrient management) can play a significant role in this regard. Agricultural producers should take advantage of soil and plant management techniques that increase plant productivity and reduce soil fertility through run-off, leaching, and nutrient deficiencies.
As the demand for fertilisers increases (> demand for food), it is important to increase crop recovery from used nutrients while reducing nutrient consumption from on-site transportation. Therefore, to improve nutrient availability and nutrient utilisation efficiency, the following points must be considered.
1). Measurement of nutrient supply capacity in the soil.
2). Improve plant genetics and crop management practices.
3). Improving crop management and food management techniques to include food sources, rates, times, and locations.
Plant factors for soil fertility management
Improving nutrient efficiency includes increasing the ability of plants to absorb nutrients from the soil, primarily from the effects of ecological root biochemistry on plant root structure, and the biochemistry of ecological roots. Enhancing the genetics of related plants and improving their nutritional metabolism. For example, the excretion of organic acids from roots between plant species and the genetic variations within them have been shown to increase soil solubility and soil motility, thus increasing phosphorus utilisation efficiency. In addition, the leakage of phytates from plant roots is genetically controlled. Therefore, GM plant growth that increases phytase concentration in roots can increase phosphorus minerals and phosphorus uptake.
Nutrient deficiencies in soil
It is estimated that 5% of cultivated soils globally have problems restricting growth in terms of both mineral deficiencies and toxicity. Therefore, an important aspect of plant nutrition is to maintain soil fertility so that it can provide the growing plants with the right amount of nutrients at the right time. The nutrient supply and plant growth are often caused by soil conditions affecting factors such as soil pH and redox status, the presence of mineral nutrients, and the number of toxins in the soil solution. Estimating the size of existing botanical plants is a major challenge in plant nutrition. However, it is not only the properties of the soil that determine the nutrient providing ability of the soil. The soil also needs to keep the roots growing for the growing plants to get enough of the available nutrients. In this regard, it is important to activate the soil microbiome.
Addition of organic and inorganic nutrients
To maintain soil fertility, nutrients are added as organic or inorganic fertilisers to ensure that large amounts of nutrients reach the growing plants. In Denmark, the results of a long-term fertilisation experiment involving the use of various NP fertilisers and animal fertilisers concluded that balanced fertilisers are important in maintaining high and stable yields of crops. Availability of soil nutrients and efficient use of nutrients by crop plants are greatly important for optimisation of food production. It has also been concluded that direct carbon input from animal manure is a more effective factor in increasing the amount of carbon in the soil through the application of mineral fertilisers.
Enhancing fertiliser use efficiencies
Fertiliser use needs to be improved to reduce costs and damage to the environment. The co-management strategy is based on applying the right fertilisers at the right rate at the right time and recycling nutrients if possible. In recent years, there has been an increasing interest in industrial and urban waste rivers for the use of phosphorus (P) in agriculture. It is rich in known P that begins to secrete Struvite (MgNH4PO4.6H2O). In one study, steroids were used as an alternative fertiliser for phosphorus and their effects with soluble fertiliser P (KH2PO4) were compared with a source of narrow-leaf lupine P. Their results show that plant-bearing P fertiliser is more efficient than soluble P fertiliser under both acidic and alkaline conditions. Struvite acts as a slow-release P fertiliser and plants can be used to release carboxylates, alter root shape and change root shape (for example, by increasing the length of the roots). It has been used successfully in various parts across the globe and beneficial results have been confirmed by various scientific studies.