Soil health is essential to plant health because soil’s biological, physical and chemical properties play an important role in growth and nourishment of plants.
The biological properties of soil refer to the bacteria, fungus, larvae and other microbes that live in soil. These play a vital role in circulating nutrients and converting nitrogen to organic matter.
The physical properties of soil include its capacity to retain water and moisture, its texture and compactness and aeration. These properties determine plant health as good soil tilth ensures better root development and nutrient capture.
Salt content, pH levels and nutritional value of soil comes under its chemical properties. These determine the nutritional value of the plants especially in the food crops. Soils pass their nutrition to the plants, thereby making them available for human consumption. Though, soils which have excessive nitrogen are more susceptible to pest attacks and further can pollute the water runoff.
It is a combination of these properties that form a close association between soil health and plant health. However, in the last 150 years, we have lost half of the available soil[1]due to the inefficient agriculture practices. It is also estimated that at least 70% of the farms in India are moving towards conditions that would not support farming for long[2].
With 2020 as the International year of plant health (#IYPH2020), let us revisit how we can conserve soil health –
- Substitute tilling with modern farming practices: Excessive tilling increases oxygen in the soil and not only stimulates microbes but also decomposes organic matter. Over time, this reduces the organic matter in the soil reducing soil health considerably.
- Using cover crops: Cover crops help enhance organic matter of the soil through their biomass. In addition, cover crops such as nitrogen fixing legumes add nitrogen to the soils and crops that host mycorrhizal fungi expedite the return of good fungus to the soils.
- Reduce pesticide use: Reducing use of pesticides immediately improves the quality of the soil but we are dependent on them to ward off pests. An alternate is to use seed science with pest resistance capabilities so that the plants are equipped to fight off pests.
Also read: The role of integrated pest management in Plant health
- Crop rotation: Traditional practices such as crop rotation are important to break pest cycles and manage weeds. Estimates suggest that in one year, weeds can rob nutrition from plants which could have helped feed a billion people[3]. This also allows farmers to plan their crop cycles, application methods and reduce use of fertilizers.
With its impact on plant health, soil health also tends to have an impact on human health. About 95% of the food comes from topsoil[4] and 80% of average calories consumption comes from crops grown directly in soil. Hence, what we need right now is an agricultural system with core focus on healthy soil because that would form the foundation of bountiful and nutritional crops.
[1]https://www.worldwildlife.org/threats/soil-erosion-and-degradation.
[2]https://www.businesstoday.in/magazine/the-buzz/the-three-i-of-farming/story/304085.html
[3]https://medium.com/@gmoanswers/the-largely-unknown-benefits-of-gmos-on-soil-health-e31915eaa44f
[4]https://www.theguardian.com/us-news/2019/may/30/topsoil-farming-agriculture-food-toxic-america
