Lesson 1. Soil fertility and a paradigm shift to soil health

SOIL02 provides an educated perspective of soil as an integral component of agriculture and earth itself. This perspective includes the management practices, importance and implications to agriculture and the environment. It aims to develop an appreciation of the soil and the services it provides to mankind, and an ability to conceptualize interventions to related problems.

1. SOIL FERTILITY Soil02 Lesson 1

2. SOIL FERTILITY DEFINED SOIL FERTILITY – the overall ability of a soil to support vigorous crop growth by ensuring adequate plant nutrients in balanced proportion and suitable conditions for water uptake, and by providing favorable conditions for root growth and development

3. What is a fertile soil? A fertile soil is essential for optimum productivity, profitability, protection of ground water quality and soil from erosion. Soil fertility is affected by physical, chemical and biological soil properties, which are inter-related with each other. Better management of physical and chemical soil fertility improves soil biological fertility, which in turn can be further enhanced by good agronomic/cultural practices. Hence, soil fertility is a key to sustainable agriculture .

4. SOIL FERTILITY AND ITS RELATIONSHIP WITH OTHER SOIL PROPERTIES

5. SOIL FERTILITY AND ITS RELATIONSHIP WITH OTHER SOIL PROPERTIES Physical properties: The capacity of soil to provide physical conditions that support plant productivity, reproduction and quality without leading to loss of soil structure or erosion and supporting soil biological and chemical processes Chemical: The capacity of soil to provide a suitable chemical and nutritional environment for the plants and foraging animals for productivity, reproduction and quality in a way that supports beneficial soil physical and biological processes, including those involved in nutrient cycling. Biological: The capacity of organisms living in soil to contribute to the nutritional requirements of plants and foraging animals for productivity, reproduction and quality while maintaining biological processes that contribute positively to the physical and chemical state of the soil.

6. A paradigm shift from soil fertility to soil health and quality Soil health has been defined as: “continued capacity of soil to function as a living system.

7. A healthy soil does: maintain a diverse community of soil organisms that help to control plant disease, insect and weed pests, form beneficial symbiotic associations with plant roots, recycle essential plant nutrients, improve soil structure with positive repercussions for soil water and nutrient holding capacity, and ultimately improve crop production”. not pollute the environment; rather, it contributes to mitigating climate change by maintaining or increasing its carbon content (FAO, 2008).

8. A comparison of soil fertility and soil health SOIL FERTILITY Ability of the soil to support vigorous crop growth by ensuring adequate plant nutrients in balanced proportion and suitable conditions for water uptake, and by providing favorable conditions for root growth and development SOIL HEALTH Soil health – the capacity of soil to function as a living system Soil quality – the ability of the soil, within its natural or managed ecosystems, to sustain productivity, enhance water and air quality, support human and animal health, and habitation

9. A comparison of soil fertility and soil health Crop production Sustenance of biological functions, maintenance of environmental quality and enhancement of plant and animal health

10. A comparison of soil fertility and soil health Plant growth, development and yield Plant growth, development and yield Soil health indicators including soil fertility and all the properties of soils Ecosystem services performed by soils

11. Question of the Day This is defined as the continued capacity of the soil to function as a living system.