Toxicity fluctuations caused by fertilizing 3 tons of CaCO3 after 45 days (without alum washing) (ppm).

Table 1: Toxicity fluctuations caused by fertilizing 3 tons of CaCO3 after 45 days (without alum washing) (ppm).

Deep (cm)	pH		Fe2+		Fe3+		Al3+		SO₄²-
Deep (cm)	Before	After	Before	After	Before	After	Before	After	Before	After
Have fertilized 3 tons CaCO₃
0-20	3.9	3.4	1.901	1.064	374	1.560	792	899	3.888	1.857
20-40	3.5	5.1	273	155	578	1.134	1.168	1.192	3.840	2.438
Do not fertilize CaCO₃
0-20	3.9	3.6	1.901	1.981	374	1.324	789	802	3.870	3.890
20-40	3.5	3.2	270	355	570	1.144	1.068	1.098	3.856	3.868