Pengiraan C / N Bahan Makanan

Table 3. Characteristics of common composting materials

Material	Nitrogen (dry weight) (%)	C:N (dry weight)	Moisture Content (%)	Bulk Density @Moisture Content (kg/m3)
Beef
- Feedlot with bedding	1.3	1.8	68	710
Dairy
- Solid manure handling	1.7	18	79	710
- Liquid slurry	2.40 - 3.60	16	88 – 92	990
- Solids separated from slurry	1.45	23	77	650
Pigs
- Liquid slurry	0.15 - 5.00	20	93 - 99	1000
- Solids separated from slurry	0.35 - 5.00	1.9	75 – 80	270 - 860
Poultry
- Broiler breeder layer	3.6	10	46	470
- Broiler litter	4.7	15	25	330
- Turkey litter	4.2	14	33	380
Horse Manure with Bedding	1.40 - 2.30	22 - 50	59 – 79	725 - 960
- with straw	1.5	27	67	-
- with shavings	0.9	65	72	-
Sheep Manure	1.30 - 3.09	13 – 20	60 – 75	-
Straw
- general straw	0.30 - 1.10	48 - 150	27-Apr	58 - 357
- oat straw	0.60 - 1.10	48 – 98	14	130 - 192
- wheat straw	0.30 - 0.50	100 - 150	10	135
- barley straw	0.75 - 0.78	-	18-Dec	-
Legume Grass Hay	1.80 - 3.60	15 – 19	10 – 30	-
Cardboard	0.1	563	8	154
Leaves 0.50	1.3	40 – 80	38	60 - 80
Paper	0.20 - 0.25	127 – 178	18 – 20	130
Sawdust	0.06 - 0.80	200 – 750	19 – 65	207 - 267
Woodwaste (Chips)	0.04 - 0.23	212 – 1313	15 – 40	264 - 368

Blending Sample Calculation

	Appendix A1
	Symbols
	a				= total weight of ingredient a
	b				= total weight of ingredient b
	c				= total weight of ingredient c
	M				= desired mix moisture content
	Ma, Mb, Mc…				= moisture content of ingredients a, b, c
	%Ca, %Cb, %Cc…				= % carbon of ingredients a, b, c… (on dry weight basis)
	%Na, %Nb, %Nc…				= % nitrogen of ingredients a, b, c,… (on dry weight basis)
	R				= desired C:N ratio of mix
	Ra, Rb				= C:N ratio of ingredients a, b, c
	.
	Appendix A2
	Formulas for Only Two Ingredients
	Required amount of ingredient a per kg b
	To obtain desired C:N ratio:				a = % Nb x (R-Rb) x (1-Mb) .>..% Na (Ra-R) (1-Ma)
	.
	To obtain desired moisture content:				a = Mb-M .>..M-Ma
	.
	Appendix A3
	Formulas for a Mix of Materials
	C:N ratio				= weight of C in ingredient a + weight of C in b + weight of C in c +… .>...>..weight of N in a + weight of N in b + weight of N in c +… = [%Ca x a x (1-Ma)] + [%Cb x b x (1-Mb)] + [%Cc x c x (1-Mc)] > [%Na x a x (1-Ma)] + [%Nb x b x (1-Mb)] + [%Nc x c x (1-Mc)]
	.
	Moisture content				= weight of water in ingredient a + weight of water in b + weight of water in c + . total weight of all ingredients = (a x Ma) + (b x Mb) + (c x Mc) … .>...>.>....a + b + c + ...0
Example Assume a broiler breeder farm has manure to compost and that sawdust will be used as a bulking agent. How much sawdust and water needs to be added to the manure to have a good compost mix? Step 1. Determine the approximate nitrogen, carbon, moisture, and bulk density from Table 3 in Chapter 2.
Material				Nitrogen (dry weight) (%)		C:N (dry weight)	Moisture Content (%)		Bulk Density @ Moisture Content(kg/m3)
Broiler Breeder Manure				3.60		10	46		470
Sawdust				0.06 - 0.80		200 - 750	19 - 65		207 - 267
Note: For a range of numbers, take the average if there has been no analysis performed.
Sawdust				0.43		475	42		237
. Step 2. Using the formula for two ingredients from Table 3, determine the amount of sawdust (a) needed for each kg of manure, (b) to give a desired C:N ratio (R) of 30.
Given:		b. Ma. Mb. Ra. Rb. %Na. %Nb.	= 1 kg of broiler breeder manure = 0.20 (for this example 20% was selected) = 0.46 (46% moisture content of manure ) = 500 (for this example C:N of 500 was selected) = 10 (C:N ratio of manure) = 0.1 (for this example 0.1% was selected) = 3.6 (% nitrogen in manure)
Determine:		a (weight of sawdust needed) for the desired C:N ratio of R = 30 a = %Nb x (R-Rb) x (1-Mb) .....%Na (Ra-R) (1-Ma)						(Appendix A2)
Calculation:		a = 3.6 x (30-10) x (1-0.46) = 1.0 .....0.1 (500-30) (1-0.20)
Answer:		For each kg of manure, add 1.0 kg of sawdust to obtain a C:N ratio of 30.

.

Step 3. Check the mix moisture content (M.C.) using the moisture content formula in Appendix A2.
Given:	a. b. Ma. Mb.	= 1.0 kg weight of sawdust from Step 2 = 1.0 kg weight of manure = 0.20 (for this example 20% was selected) = 0.46 (46% moisture content of manure)
Determine:	M.C. (mix moisture content) M.C. = (a x Ma) + (b x Mb) ..................a + b		(Appendix A3)
Calculation:	M.C. = (1 x 0.20) + (1 x 0.46) = 0.33 or 33 % ........................1 + 1
Answer:	This starting moisture content of 33% is too low, since ideal moisture content runs from 50 to 60%.
Step 4. Adjust moisture content to 55% using the two-ingredient formula from Appendix A2.
Given:	b. M. Ma. Mb.	= 1 kg of manure/sawdust mix = 0.55 (55% desired moisture content) = 1.0 (100% moisture content of water) = 0.33 (33% moisture content of manure/sawdust mix)
Determine:	‘a’ quantity of water required a = Mb - M ......M - Ma
Calculation:	a = 0.33 - 0.55 = 0.49 ......0.55 - 1.00
Answer:	Add 0.49 kg of water for every 1.0 kg of manure/sawdust mix.
. Step 5. Determine how much manure, sawdust and water to mix.
Given:	Tractor bucket volume = 2.0 m3 Manure bulk density = 470 kg/m3 Sawdust bulk density = 207 kg/m3
Determine:	Volume of manure, sawdust, and water
Calculation:	One bucket of manure weighs 2.0 m3 x 470 kg/m3 = 940 kg Since an equal weight of manure and sawdust is wanted, add 940 kg of sawdust or 940 kg / 207 kg/m3 = 4.54 m3 of sawdust This is equal to 4.54 m3 / 2.0 m3 per bucket = 2.27 buckets of sawdust For each bucket of manure used, there will be a total manure/sawdust mix weighing 940 kg + 940 kg = 1840 kg Similarly, for each bucket of manure used, add: 0.49 kg of water / kg of mix x 1840 kg = 902 kg of water (902 L of water)
Answer:	For each bucket of manure, add 2.27 buckets of sawdust and 902 litres of water.