Effects of maize plant type and row spacing on the field microclimate and yield of intercropping ginger

Figures & data

Table 1. Maize cultivars for the experiment.

NO.	Cultivar	Plant type	Plant height (cm)	Ear length (cm)	Relative maturity (d)
A (ZH 311)	Zhenghong 311	Tall	290	19.5	115
B (ZH 6)	Zhenghong 6	Short	270	17.8	110

Figure 1. Meteorological conditions in ginger growing period.

Figure 2. Field layout of different row spacing intercropping patterns.

Figure 3. Differences in soil temperature in different treatments.

ST, shading treatment; CK, pure without shading. Values with different lowercase letters are significantly different with p < 0.05 according to the least significant difference test.

Table 2. Variance analysis of soil and canopy indexes.

	Treatments	Soil temperature	Soil moisture	Canopy temperature	Canopy humidity	Shading rate
F value	Years (Y)	852.68**	4000.78**	2.91^ns	4.63*	0.03^ns
	Variety (V)	100.70**	99.555**	0.72^ns	8.29**	34.62**
	Row spacing (R)	521.38**	958.20**	53.79**	137.02**	302.93**
	Y×V	3.38^ns	0.38^ns	1.26^ns	0.90^ns	0.19^ns
	Y×R	2.63^ns	22.01**	0.49^ns	0.16^ns	0.19^ns
	V×R	0.31^ns	1.43^ns	3.29^ns	2.20^ns	14.84**
	Y×V×R	3.12^ns	0.93^ns	0.39^ns	0.25^ns	3.45*

**p < 0.01; *p < 0.05; ^nsNot significant.

Figure 4. Differences in soil moisture content in different treatments.

ST, shading treatment; CK, pure without shading. Values with different lowercase letters are significantly different with p < 0.05 according to the least significant difference test.

Figure 5. Diurnal variation in canopy temperature under different treatments.

A1, ZH 311-2 m; A2, ZH 311-3 m; A3, ZH 311-4 m; B1, ZH 6-2 m; B2, ZH 6-3 m; B3, ZH 6-4 m; ST, shading treatment; CK, pure without shading.

Figure 6. Diurnal variation in canopy humidity under different treatments.

A1, ZH 311-2 m; A2, ZH 311-3 m; A3, ZH 311-4 m; B1, ZH 6-2 m; B2, ZH 6-3 m; B3, ZH 6-4 m; ST, shading treatment; CK, pure without shading.

Figure 7. Shading rate of ginger in different treatments.

A1, ZH 311-2 m; A2, ZH 311-3 m; A3, ZH 311-4 m; B1, ZH 6-2 m; B2, ZH 6-3 m; B3, ZH 6-4 m; ST, shading treatment; CK, pure without shading. Values with different lowercase letters are significantly different with p < 0.05 according to the least significant difference test.

Table 3. Morphological indices and ginger yield under different intercropping patterns.

Treatments	Plant height (cm)	Stem diameter (mm)	Branching number	Yield (t ha^−1)
2017
A1	95.94 a	11.36 a	16.28 a	49.65 a
A2	88.04 bc	9.87 bc	14.44 bc	39.34 c
A3	80.76 de	9.24 de	13.61 c	37.32 cd
Average	88.25 A	10.16 A	14.78 A	42.10 A
B1	91.57 ab	10.25 b	15.72 ab	45.03 b
B2	85.01 cd	9.32 cd	13.83 c	38.74 c
B3	80.28 e	8.71 e	13.46 c	35.33 d
Average	85.62 B	9.43 B	14.34 A	39.70 B
IC	86.93 b	9.79 b	14.56 b	40.90 b
ST	108.53 a	12.19 a	18.49 a	61.65 a
CK	77.87 c	8.01 c	12.55 c	34.35 c
2018
A1	92.62 a	10.86 a	16.51 a	47.34 a
A2	84.93 c	9.81 c	14.17 c	39.36 b
A3	79.13 de	9.13 d	13.27 de	37.00 c
Average	85.56 A	9.93 A	14.65 A	41.23 A
B1	87.97 b	10.06 b	15.50 b	45.64 a
B2	81.61 d	9.17 d	13.32 d	38.07 bc
B3	76.80	8.33 e	12.76 e	34.19 d
Average	82.12 B	9.19 B	13.86 B	39.30 B
IC	83.84 eb	9.56 b	14.26 b	40.27 b
ST	104.65 a	12.19 a	17.91 a	59.30 a
CK	74.91 c	8.01 c	12.29 c	31.11 c
F value
Years (Y)	21.27**	8.57**	2.45^ns	2.57^ns
Variety (V)	20.49**	85.97**	10.24**	29.80**
Row spacing (R)	122.09**	169.20**	73.12**	272.08**
Y×V	0.36^ns	0.02^ns	0.82^ns	0.35^ns
Y×R	0.17^ns	0.74^ns	0.69^ns	0.16^ns
V×R	1.80^ns	1.88^ns	0.53^ns	2.69^ns
Y×V×R	0.15^ns	1.18^ns	0.03^ns	2.38^ns

A1, ZH 311–2 m; A2, ZH 311–3 m; A3, ZH 311–4 m; B1, ZH 6–2 m; B2, ZH 6–3 m; B3, ZH 6–4 m; ST, shading treatment; CK, pure without shading. Values with different lowercase letters are significantly different with p < 0.05 according to the least significant difference test. **p < 0.01; *p < 0.05; ^ns Not significant.

Figure 8. Correlation analysis between field microclimate and ginger yield.