Intensive Integrated Farming System Models
Area
- Out of 25 m/ha of problematic acid soils of India with pH below 5.5, NE region represents 54% of the total area whereas it occupies only 8% of the total geographical area.
Causes of soil acidity
- Natural process: high rainfall, acidic parent material, type of vegetation
- Human induced: Soil erosion accompanied by loss of top fertile soils and exposure of poor fertile subsoil. In few pockets acidity is also induced by application of nitrogenous fertilizers
Problems
- Toxicity of aluminium mainly
- Deficiency of bases (calcium , magnesium and potassium)
- Low availability of phosphorus caused by the high fixation capacity of soil
- Reduction of soil biological activities
- Impairment of nitrogen fixation by legumes and deficiency of molybdenum
- Iron and manganese toxicities in submerged soils
Management
- Liming of acid soils to raise the soil pH to 5.5 to neutralize toxic aluminum i.e. make the soil to suit the plant
- Growing of acid tolerant plants: select the plants to suit the acid soil conditions
- Breeding of acid tolerant crops especially pulses, oilseeds and cereals
Technology available
- Ready reckoner for acid soils to raise soil pH to 5.5 by liming
- Application of 500 kg lime in furrows to each crop
- Tolerant plants: pineapple, coffee, tea, rubber, sweet potato, casava, potato, rice, pigeonpea, fingermillet, buckwheat, ricebean, colocasia, allocasia, ginger, turmeric, etc.
Lime requirement of soils to achieve the pH 5.5 as affected by pH, organic matter and clay content of soils (t/ha)*.
| Soil pH | Organic matter, 2% | Organic matter, 4% | Organic matter, 6% | Organic matter, 8% | ||||||||||||
| Clay (%) | Clay (%) | Clay (%) | Clay (%) | |||||||||||||
| 10 | 15 | 20 | 25 | 10 | 15 | 20 | 25 | 10 | 15 | 20 | 25 | 10 | 15 | 20 | 25 | |
| 4.5 | 3.56 | 3.83 | 4.11 | 4.39 | 3.72 | 4.00 | 4.28 | 4.56 | 3.89 | 4.17 | 4.44 | 4.72 | 4.05 | 4.33 | 4.61 | 4.89 |
| 4.6 | 3.15 | 3.42 | 3.70 | 3.98 | 3.32 | 3.59 | 3.87 | 4.14 | 3.49 | 3.77 | 4.04 | 4.32 | 3.66 | 3.93 | 4.21 | 4.49 |
| 4.7 | 2.74 | 3.01 | 3.29 | 3.60 | 2.91 | 3.18 | 3.34 | 3.62 | 3.08 | 3.36 | 3.63 | 3.91 | 3.24 | 3.52 | 3.80 | 4.08 |
| 4.8 | 2.25 | 2.53 | 2.81 | 3.09 | 2.42 | 2.70 | 2.98 | 3.26 | 2.59 | 2.87 | 3.14 | 3.42 | 2.76 | 3.03 | 3.31 | 3.59 |
| 4.9 | 1.93 | 2.22 | 2.49 | 2.75 | 2.10 | 2.38 | 2.66 | 2.93 | 2.27 | 2.54 | 2.82 | 3.10 | 2.43 | 2.71 | 3.00 | 3.27 |
| 5.0 | 1.52 | 1.80 | 2.08 | 2.35 | 1.69 | 1.97 | 2.24 | 2.52 | 1.86 | 2.13 | 2.41 | 2.69 | 2.02 | 2.30 | 2.58 | 2.86 |
| 5.1 | 1.11 | 1.40 | 1.68 | 1.94 | 1.29 | 1.56 | 1.84 | 2.12 | 1.46 | 1.73 | 2.01 | 3.29 | 1.62 | 1.90 | 2.18 | 2.46 |
| 5.2 | 0.71 | 1.00 | 1.27 | 1.56 | 0.90 | 1.16 | 1.43 | 1.71 | 0.06 | 1.33 | 1.61 | 1.90 | 1.22 | 1.50 | 1.78 | 2.06 |
| 5.3 | 0.31 | 0.59 | 0.86 | 1.13 | 0.48 | 0.76 | 1.03 | 1.31 | 0.64 | 0.92 | 1.20 | 1.48 | 0.81 | 1.09 | 1.37 | 1.64 |
| 5.4 | 0.18 | 0.44 | 0.72 | 0.07 | 0.34 | 0.62 | 0.90 | 0.23 | 0.51 | 0.82 | 1.10 | 0.40 | 0.68 | 0.96 | 1.23 | |
Extent of acid soils in NE region
| States | pH <5.5 | pH 5.5.-6.5 |
Total acid soil m/ha |
Geog. area m/ha |
% G. area of acid soil |
| Arunachal Pradesh | 6.52 | 0.27 | 6.79 | 7.786 | 81.08 |
| Assam | 2.33 | 2.33 | 4.66 | 7.844 | 59.41 |
| Manipur | 1.87 | 0.32 | 2.19 | 2.233 | 98.07 |
| Meghalaya | 1.19 | 1.05 | 2.24 | 2.243 | 99.87 |
| Mizoram | 1.27 | 0.78 | 2.05 | 2.208 | 97.20 |
| Nagaland | 1.60 | 0.05 | 1.64 | 1.658 | 99.50 |
| Sikkim | 0.60 | - | 0.60 | 0.710 | 84.51 |
| Tripura | 0.81 | 0.24 | 1.05 | 1.049 | 100.00 |
| Total NE | 16.19 | 5.04 | 21.23 | 26.219 | 80.97 |
| India | 30.00 | 58.94 | 89.95 | 328.726 | 27.36 |
| % NE of India | 53.97 | 8.41 | 23.60 | 7.97 | 6.45 |