Intercropping of Gramineous Pasture Ryegrass (Lolium perenne L.) and Leguminous Forage Alfalfa (Medicago sativa L.) Increases the Resistance of Plants to Heavy Metals

Table 4

Soil enzyme activities after plant harvest under the different treatments.

Treatment	Urease	Saccharase	Alkaline phosphatase	Catalase	Polyphenol oxidase
	(NH3^+-N mL^−1g^−124 h^−1)	(C6H12O6 mg^−1g^-124 h^−1)	(μg PNP g^−1h^−1)	1.1 mol L^−1 KMnO4 mL^−1g^−1 20 min^−1)	(Purpurogallin mg^−1g^−1 2 h^−1)
Control	2.61 ± 0.1^ab	7.28 ± 1.1^d	1.45 ± 0.06^bc	1.56 ± 0.1^b	3.40 ± 0.1^a
MR	2.79 ± 0.07^a	15.3 ± 0.2^b	1.50 ± 0.1^b	2.11 ± 0.2^a	3.04 ± 0.2^b
MA	2.60 ± 0.1^b	11.2 ± 2.4^c	1.29 ± 0.1^c	1.98 ± 0.1^a	3.47 ± 0.2^a
IRA	2.70 ± 0.01^a	20.5 ± 0.1^a	1.70 ± 0.09^a	2.18 ± 0.1^a	3.37 ± 0.3^a

Note. Values are the means ± standard error (). Means followed by the same letter in the same column are not significantly different at . MR: monoculture ryegrass; MA: monoculture alfalfa; IRA: intercropping of ryegrass and alfalfa.