Table 1 Factor rating of land quality for low land rice

Land quality	Diagnosti c Factor	Unit	Factor rating
			1.0	0.8	0.5	0.2	0.0
Water Availability (W)	Rainfall/Irrigation	m.m.	>1800 or irrigated	1200-1800	1200-900	900	-
Nutrient Availability Index (NAI) NAI= NN x P x K x pH	N P K pH	- % ppm meq/100g -	>0.9 >0.5 >50 >0.5 6.0-7.5	0.04-0.09 0.5-0.08 25-50 0.2-0.5 5.5-6.0	0.02-0.4 0.08-0.4 10-25 0.1-0.2 4.5-5.5	<0.2 <0.4 <10 <0.1 <4.5	- - - - - -
Water and Nutrient Retentions (R)	Soil Texture/ Particle size		SCL, SL, SC, CL L	SL AC	LS, GS	SS	Rock Land
	SCL = silty clay loam L = Loam LS = Loam Sand SL = silty loam SL = Sandy loam GS= Gravel soil SC=silty clay AC= Alluvial complex SS = Skeletal soil CL= clay loam
Salt hazard (S)	Salinity of Soil	-	Non saline	Low saline	High saline	Vary high saline	-
Topography (T)	Landform and slope	-	F	LT/MT/M and slope <2.0%	LT/MT/M/L and slope 2-5%	MT/M/ and slope >5%, HT	-
	F= Flood plain LT -= Low terrace MT = Middle terrace				HT = High terrace M = Mountain L = Leave