Cultivation of land to some extent is necessary for the income to be treated as agricultural income. While growing of crops is covered under agriculture's ambit, activities like poultry farming, dairy farming, aquaculture and sericulture on the same land are not treated as agricultural activity.
Please refer to the caselaw.Commissioner of Income-tax Vs R.Venkataswamy Naidu 1956 29 ITR 529 (SC) .In the said case Supreme court evaded the question whether Income from milk is agricultural income on technical grounds. How ever S.C.cited some caselaws where income from sale of milk was said to be Agricultural Income. However,S.C. abstained from commenting on the rightfulness of the decisions. But the caselaw makes good reading .Please check out the following link.