Table 7. Acid phosphatase activity as affected by main effects of P application and subplot effects of cropping system in 2011 and 2012.

Year	P rate (kg ha−1)	Acid phosphatase activity of intercropped and weighted means of corresponding monocropped crops (µg p-nitrophenolg−1 soil h−1)
		Maize + faba bean		Maize + soybean		Maize + chickpea		Maize + turnip		Average
		Mono	Inter	Mono	Inter	Mono	Inter	Mono	Inter	Mono	Inter	Mean
2011	0	37.8ab	41.1ab	53.0a	54.1a	28.9b	44.6ab	27.3b	50.9a	36.8a	47.8a	42.2B
	40	32.9c	54.3ab	49.7b	62.7a	34.2c	52.4ab	46.4b	46.0b	40.8b	53.9a	47.3B
	80	60.8ab	56.4ab	76.1a	69.7ab	52.0b	63.4ab	50.4b	51.2b	59.8a	60.2a	60.0A
	Mean	43.8CDE	50.6BCD	59.6AB	62.2A	38.4E	53.5ABC	41.4DE	49.4BCD	45.8A	53.9A	49.8
2012	0	159.7a	153.0a	179.4a	153.4a	145.3a	133.7a	144.9a	132.2a	157.3a	143.1a	150.2A
	40	96.6b	115.1b	120.0b	183.5a	107.6b	121.9b	98.8b	127.0b	105.8b	136.9a	121.3A
	80	134.1ab	137.6ab	173.6a	186.3a	135.5ab	112.0b	134.6ab	150.9ab	144.6a	146.7a	145.6A
	Mean	130.1BC	135.2BC	157.7AB	174.4A	129.5BC	122.5C	126.1BC	136.7BC	135.8A	142.2A	139.0
ANOVA
	Year (Y)				<0.001						<0.001
	P rate (P)				0.002						0.077
	Cropping system (C)				0.000						0.253
	Y×P				0.006						0.096
	Y×C				0.400						0.886
	P×C				0.647						0.253
	Y×P×C				0.729						0.371

Values are means of three replicates. Values followed by the same lowercase letters are not significantly different among different cropping systems with the same P rate in one year at the 5% level by LSD (horizonal comparison); values followed by the same capital letters are not significantly different among different P rates (vertical comparison) or among different cropping systems (horizonal comparison) in one year at the 5% level by LSD. Values under ANOVA are the probabilities (P values) of the sources of variation.