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The four main types of agricultural residues are (i) feed and seed crop, (ii) fruit and nut crop, (iii) vegetable crop, and (iv) nursery crop and vary in composition (Table A-7).

Table A-7 Properties of various agricultural residues.

Agricultural residues	Volatiles (%)	Fixed carbon (%)	Ash (%)	HHV (Kj/kg)	LHV (Kj/kg)	Density (%)
Arhar stalk	83.47	14.76	1.77	15.00	14.85
Bagasse	75.10	16.87	8.03	19.50	19.37	40 – 60
Bamboo dust	75.32	15.59	9.09	16.02	15.87
Cotton stalk	70.89	22.43	6.68	18.26	17.85	10 – 20
Coconut coir	70.30	26.77	2.93	18.20	17.79	7 – 8
Corn cob	80.20	16.20	3.60	15.58	15.23	10 – 20
Dhaincha stalk	80.32	17.01	2.67	19.63	19.43
Groundnut shell	68.12	24.97	6.91	17.20	17.06
Jute stick	75.33	19.00	5.67	19.45	19.01
Mustard shell	70.09	14.48	15.43	17.61	17.47
Pine needle	72.38	26.12	1.50	20.12	19.97
Rice husk	60.64	19.90	19.48	13.38	13.24	9
Sal seed leaves	60.03	20.22	19.75	18.57	18.42
Sal seed husk	62.54	28.06	9.40	20.60	20.13

Field and seed crop residues are the materials remaining above the ground after harvesting, including straw or stubble from barley, beans, oats, rice, rye, and wheat, stalks, or stover from corn, cotton, sorghum, soybeans, and alfalfa. The moisture content (wet basis) of these residues ranges from 8 to 80%. The typical bulk density of loose straw and stover varies from 1 to 3 lb/ft³ and the bulk density of baled straw and stover varies from 7 to 12 lb/ft³. If pelletized, the bulk density increases to 35 to 45 lb/ft³.

Fruit and nut crop residues include orchard pruning residues and brushes. The types of fruit and nut crops include almonds, apples, apricots, avocados, cherries, dates, figs, grapefruit, grapes, lemons, limes, olives, oranges, peaches, pears, plums, prunes, and walnuts. The moisture content (wet basis) of these residues ranges from 35 to 55%. Hammer-milled orchard pruning residues have a bulk density of from 9 to 12 lb/ft³.

Vegetable crop residues consist mostly of vines and leaves that remain on the ground after harvesting. The types of vegetable crops include such plants as artichokes, asparagus, cucumbers, lettuce, melon, potatoes, squash, and tomatoes. The moisture content (wet basis) of these residues is usually greater than 90%.

Nursery crop residues include the pruning residues and trimmings taken from the plants during their growth and in the preparation for market. There are more than 30 different species of nursery crops (such as flowers and indoor plants) that are grown. The moisture content of these residues is usually dependent on the type of crop that is being grown.

Quantifying the amounts and types of agricultural residues generated in each of the crop categories is extremely difficult, as it would require conducting comprehensive research throughout the state with continuous updates to the compiled data. Without ongoing data collection, any quantification estimates would only be valid for the time frame that the study was done and would be susceptible to ongoing market changes. Any quantification of agricultural residue tonnages should be viewed with these inherent limitations in mind and the tonnages quoted should not be considered absolute values.

See also: Agricultural Residues, Agricultural Waste, Residues, Rice Straw, Wheat Straw.