{'green manure': [2, 0, 0, 1], 'manure': [0, 0, 0, 2], 'soil': [7, 0, 4, 7], 'organic plant material': [0, 0, 0, 1], 'plant material': [0, 0, 0, 1], 'biomass': [1, 0, 0, 0], 'nitrogen': [1, 1, 0, 2], 'crop': [0, 0, 1, 1], 'fertility': [5, 0, 1, 4]}