Growth and yield of maize using two tillage systems in crop rotation of paddy fields

Figures & data

Figure 1. Changes in daily mean temperature (a), duration of sunshine (b), and precipitation (c) during the growing season (Morioka, Iwate).

Notes: E: Early part of the month; M: Middle of the month; L: Late part of the month.

Figure 2. Changes in daily mean temperature(a), duration of sunshine (b), and precipitation (c) during the growing season (Shiwa, Iwate).

Notes: E: Early part of the month; M: Middle of the month; L: Late part of the month.

Table 1. Soil chemical properties before cropping.

Year	Location	Tillage	pH	P-a^a (mg 100 g^−1)	K-e^b (mg 100 g^−1)	N-h^c (mg 100 g^−1)	N-n^d (mg 100 g^−1)	N-a^e (mg 100 g^−1)
2016	Morioka	RT	6.4	3.2	20.6	6.0	0.5	1.2
		PT	6.3	3.0	20.5	5.7	0.2	1.6
2017	Morioka	RT	6.3	1.8	14.5	7.6	0.4	3.1
		PT	6.4	2.1	15.6	7.8	0.3	2.2
	Hanamaki	RT	5.5	19.6	19.4	6.4	0.3	1.0
		PT	5.6	15.7	19.6	7.1	0.4	1.1

Notes: ^aAvailable phosphorus, ^bexchangeable potassium, ^chot water-extractable nitrogen, ^dnitrate nitrogen, ^eammonium nitrogen.

RT: Rotary tilling; PT: Plowing tillage.

Figure 3. Soil penetration resistance in Morioka, Iwate (a) and Hanamaki, Iwate (b).

Notes: RT: Rotary tilling; PT: Plowing tillage.

Table 2. Soil pulverization rate, seedling establishment rate, and time to silking stage.

Year	Location	Tillage	Soil pulverization rate (%)	Seedling establishment		Silking stage (DAS^a)
				Number of plants	Rate
				(plants m^−2)	(%)
2016	Morioka	RT	68	5.9	82	71
		PT	84	6.1	93	68
2017	Morioka	RT	65	6.6	90	69
		PT	79	7.1	95	68
	Hanamaki	RT	76	6.3	92	63
		PT	79	6.2	85	61
	Average	RT	70	6.2	88	70
		PT	81	6.3	91	68
		t-test	ns	ns	ns	ns

Notes: *Significant at the 0.05 probability level. ns, nonsignificant at the 0.05 probability level. t-test of soil pulverization and seedling establishment rate was conducted after angular transformation.

^aDays after sowing.

RT: Rotary tilling; PT: Plowing tillage.

Figure 4. Changes in plant height and SPAD value.

Notes: **significant at the 0.01 probability level at tillage treatment; *significant at the 0.05 probability level between tillage systems.RT: Rotary tilling; PT: Plowing tillage.

Table 3. Crop growth rate (CGR), net assimilation rate (NAR), and mean leaf area index (LAI) during bracketing silking period.

Year	Location	Tillage	CGR (g m^−2 d^−1)	NAR (g m^−2 d^−1)	LAI (m^2 m^−2)
2016	Morioka	RT	28.6	10.3	2.8
		PT	32.0	9.5	3.4
2017	Morioka	RT	31.0	6.5	4.7
		PT	36.5	7.3	5.0
	Hanamaki	RT	31.6	6.4	5.0
		PT	29.8	5.9	5.0
	Average	RT	30.4	7.8	4.2
		PT	32.7	7.6	4.4
		t-test	ns	ns	ns

Notes: ns, nonsignificant at the 0.05 probability level.

RT: Rotary tilling; PT: Plowing tillage.

Table 4. Aboveground dry weight at maturity, grain yield, and yield components.

Year	Location	Tillage	Dry weight (g m^−2)	Ear length (cm)	Kernel number (m^−2)	100 grain weight (g)	Grain yield (g m^−2)	Root lodging (%)	Stalk lodging (%)
2016	Morioka	RT	2025	18	3172	30.4	966	–	–
		PT	2172	17	3616	29.6	1071	–	–
2017	Morioka	RT	2003	15	3412	26.5	909	59	6
		PT	2073	15	3060	27.4	842	19	20
	Hanamaki	RT	2302	19	3500	32.3	1124	98	0
		PT	2409	18	3288	35.7	1170	12	11
	Average	RT	2110	17	3361	29.8	1000	79	3
		PT	2218	17	3321	30.9	1028	15	15
		t-test	*	ns	ns	ns	ns	ns	ns

Notes: *Significant at the 0.05 probability level. ns, nonsignificant at the 0.05 probability level.

RT: Rotary tilling; PT: Plowing tillage.

Table 5. Starch, CP, and mycotoxin contamination.

Year	Location	Tillage	Starch (DM^f%)	CP^a (DM^f%)	DON^b (ppm)	NIV^c (ppm)	ZEA^d (ppm)	FUM^e (ppm)
2016	Morioka	RT	69	9.0	0.8	n.d.^g	0.63	1.74
		PT	69	8.7	0.2	n.d.^g	0.01	2.42
2017	Morioka	RT	67	7.9	1.6	n.d.^g	0.09	11.54
		PT	68	7.7	2.5	0.1	0.08	6.42
	Hanamaki	RT	67	9.6	1.8	0.6	0.41	15.90
		PT	67	9.0	1.3	0.5	0.11	8.30
	Average	RT	68	8.9	1.4	n.d.^g	0.38	9.7
		PT	68	8.4	1.3	0.3	0.07	5.7
		t-test	ns	*	ns	-	ns	ns

Notes: *Significant at the 0.05 probability level. ns, nonsignificant at the 0.05 probability level. t-test of starch and crude protein was conducted after angular transformation.

^aCrude protein, ^bdeoxynivalenol, ^cnivalenol, ^dzearalenone, ^efumonisin, ^fdry matter, ^gnot detected.

RT: Rotary tilling; PT: Plowing tillage.