Innovation of strip fertilization planting for rice straw crushing with back-throwing and interrow-laying

Table 4 Analysis of variance

Evaluation index	Variation source	Sum of squares	Degree of freedom	Mean sum of square	F	Significance
Uniformity of the straw mulching Y₁	Calibration model	56.92^a	6	9.48	3.23
	A	38.28	2	19.14	6.52	**
	B	18.20	2	9.10	3.10	*
	C	0.43	2	0.21	0.07
Variability of the seed-belt width Y₂	Calibration model	53.11^b	6	8.85	15.13
	A	0.08	2	0.04	0.07
	B	9.44	2	4.72	8.07	*
	C	43.57	2	21.78	37.25	**

‘**’ means extremely significant (significance level < 0.01), ‘*’ means significant (significance level < 0.05)
^aR² = 0.91
^bR² = 0.98

ISSN: 1746-4811