Soil quality and soil health in agriculture

describes about soil quality and health and its impact on crops

1. Definition of problematic soils The ‘ problem soil ’ herein means the soil that has agricultural problems due to the soil ’ s unsuitable physical and chemical properties, or less suitable for cultivation, resulting in that crops are not able to grow and produce yields as normal. These soils always occur naturally, including saline soil, acid sulfate soil, sandy soil, skeletal soil and shallow soil.

2. Soil quality and soil health: Factors affecting soil quality and soil health. Management of soil quality and soil health . Definition of Soil quality and Soil health The term soil quality and soil health are often used interchangeably in the scientific literature; scientist, in general, prefer ‘soil quality’ and producers prefer ‘soil health’

3. Definition of Soil quality Soil quality is the capacity of a specific kind of soil to function within ecosystem and land-use boundaries, to sustain biological productivity, maintain environment quality, and sustain plant, animal, and human health .

4. Definition of Soil health Soil health is defined as the continued capacity of soil to function as a vital living system, by recognizing that it contains biological elements that are key to ecosystem function within land-use boundaries. These functions are able to sustain biological productivity of soil, maintain the quality of surrounding air and water environments, as well as promote plant, animal, and human health .

5. Factors affecting soil quality and soil health The major causes of poor soil quality are:

6. Wide gap between nutrient demand and supply, High nutrient turnover in soil plant system coupled with low and imbalanced fertilizer use, Emerging deficiency of secondary and micronutrients due to improper use of inputs such as water, fertilizers, pesticides, etc.,

7. Interpretation of results pH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 6.3 8.3 Neutral Normal soil Acidic soil Alkali soil Required lime Required gypsum

8. Electrical conductivity (EC) EC values Interpretation < 1 d S/m at 25 C Normal soil with respect to soluble salts 1- 2 d S/m at 25 C Critical to crop growth > 2 d S/m at 25 C Injurious to crops

9. Interpretation of NPK results Nutrients Low Medium High Organic carbon(%) < 0.5 0.5 – 0.75 > 0.75 Avail. N (kg/ha) < 280 280 - 560 > 560 Avail. P 2 O 5 (kg/ha) < 22.5 22.5 – 55.00 > 55.00 Avail. K 2 O (kg/ha) < 144 144 – 336 > 336

10. Interpretation of secondary nutrients Nutrients Critical level Exch. Ca ( meq /100 g) 1.5 Exch. Mg ( meq /100 g) 1.0 Avail. Sulphur (mg /kg) < 10

11. Interpretation of micronutrients results Micronutrient Extractant Critical level in soil (mg /kg) Iron (Fe) DTPA 2.5-4.5 Manganese (Mn) DTPA 2.0 -3.0 Zinc (Zn) DTPA 0.6 – 1.2 Copper (Cu) DTPA 0.2-0.5 Boron (B) Hot water 0.33-1.0 Molybdenum (Mo) Ammonium oxalate 0.04-0.1

12. N - fertilizers recommendation based on soil test results Recommended dose of N fertilizers Low available N status in soil High N status in soil < 50 kg ha -1 No change in the recommendation 51 - 100 kg ha -1 + 12.5 kg ha -1 - 12.5 kg ha -1 100 - 175 kg ha -1 + 25.0 kg ha -1 - 25.0 kg ha -1 175 - 250 kg ha -1 + 37.5 kg ha -1 - 37.5 kg ha -1 251 - 325 kg ha -1 + 50.0 kg ha -1 - 50.0 kg ha -1 For medium N status of soil – No modification in the fertilizers recommended

13. P & K fertilizers recommendations based on the soil test results Recommended P or K fertilizers Low status of P or K in soil High status of P or K in soil Phosphorus <25 kg P 2 O 5 ha -1 No change in the recommendation 26 – 75 kg P 2 O 5 ha -1 + 12.5 kg P 2 O 5 ha -1 - 12.5 kg P 2 O 5 ha -1 > 75 kg P 2 O 5 ha -1 + 25.0 kg P 2 O 5 ha -1 - 25.0 kg P 2 O 5 ha -1 Potassium <25 kg K 2 O ha -1 No change in the recommendation 26 – 50 kg K 2 O ha -1 + 12.5 kg K 2 O ha -1 - 12.5 kg K 2 O ha -1 51 – 100 kg K 2 O ha -1 + 25.0 kg K 2 O ha -1 - 25.0 kg K 2 O ha -1 101 - 175 kg K 2 O ha -1 + 37.5 kg K 2 O ha -1 - 37.5 kg K 2 O ha -1

14. Insufficient use of organic inputs, Acidification and A1 3+ toxicity, Development of salinity and alkalinity in soils,

15. Heavy metal toxicity, Disproportionate growth of microbial population responsible for soil sickness, and Natural and manmade calamities such as erosion , deforestation occurring due to rapid industrialization and urbanization, etc.

16. Management of soil quality and soil health .

17. 1. Add organic matter : Soil organic matter improves physical, chemical and biological properties of soil. 2. Avoid excessive tillage : Tillage has positive effects, but it also triggers excessive organic matter degradation, disrupts soil structure, and can cause compaction .

18. . 3. Carefully manage fertilizer and pesticide use : Fertilizer can increase plant growth and the amount of organic matter returned to the soil. They can harm beneficial organisms and pollute water and air if they are mismanaged 4. Increase ground cover : Bare soil is susceptible to wind and water erosion. Ground cover protects soil, provides habitats for larger soil organisms, such as insects and earthworms, and can improve water availability .

19. 5. Increase plant diversity : Each crop contributes a unique root structure and type of residue to the soil. A diversity of soil organisms can help control pest populations, and a diversity of cultural practices can reduce weed and disease pressures.