Performance of double cropping and relay intercropping for black soybean production in small-scale farms

Figures & data

Figure 1. Monthly average temperature and total rainfall during the period of 2009, 2010, 2011 and 30 year average E, M and L indicate early, middle and late in each month, respectively.

Table 1. Cropping patterns tested and the data of sowing and harvesting in each year.

Figure 2. Row arrangement of Kurozukin, Tanbaguro and their relay intercropping. The symbols of ○ and △ represent Kurozukin and Tanbaguro, respectively. (A) Mono cropping of Kurozukin, (B) Mono cropping of Tanbaguro. (C) Relay intercropping with Kurozukin and Tanbaguro. In relay intercropping fields, Tanbaguro was sown between the rows of Kurozukin, leading to the row arrangement as shown by (C). (D) A photograph of the field condition of relay intercropping. The photograph was taken on 20 July of 2011 (just before the harvest of Kurozukin).

Table 2. Effects of cropping patterns on the growth and yields of vegetable soybean of Kurozukin for three years.

Year		Cropping pattern	Main Stem length (cm)		Main stem node number		Branch number		Pod number (hill^−1)		Pod weight (g hill^−1)
2009		Mono	–		–		–		51.3	(1.79)	94.3	(3.84)
		D2	–		–		–		49.4	(2.81)	100	(5.74)
		R2	–		–		–		57.0	(2.10)	109	(4.60)
One-way ANOVA		F value	–		–		–		3.035		2.229
		Probability							0.123		0.189
2010		Mono	33.7	(2.45)	8.43	(0.29)	3.71	(0.14)	27.1	(4.12)	51.4	(5.61)
		D1	35.2	(3.54)	8.24	(0.36)	3.31	(0.28)	35.8	(5.80)	70.6	(13.2)
		D2	32.4	(1.09)	8.24	(0.19)	3.83	(0.41)	30.8	(5.11)	60.1	(9.45)
One-way ANOVA		F value	0.302		0.146		0.854		0.748		0.942
		Probability	0.750		0.867		0.472		0.513		0.441
2011		Mono	25.7	(2.55)	7.679	(0.55)	3.73	(0.29)	45.5	(5.31)	79.8	(8.86)
		D1	28.4	(0.87)	8.17	(0.25)	4.00	(0.25)	51.7	(4.67)	88.9	(14.6)
		D2	24.3	(2.01)	8.17	(0.08)	4.15	(0.10)	46.2	(3.49)	79.2	(5.85)
		R1	25.8	(1.13)	7.67	(0.12)	4.10	(0.31)	45.2	(6.86)	82.7	(13.3)
		R2	27.0	(2.58)	8.20	(0.26)	3.50	(0.12)	43.1	(6.78)	76.5	(12.6)
One-way ANOVA		F value	0.615		0.681		1.437		0.327		0.167
		Probability	0.662		0.621		0.292		0.854		0.950
One-way ANOVA	Year	F value	5.166		1.051		0.001		9.92		11.48
		Probability	0.085		0.363		0.975		1.25 × 10^−2**		8.90 × 10^−3**

The data are means of three replicated plots. The values in parenthesis indicate standard error of mean. The effects of cropping patterns on growth and yield in each year were analyzed by ANOVA. In addition, the difference of yield between each year was analyzed by ANOVA.

Table 3. Effects of cropping patterns on the growth and yield of vegetable soybean of Tanbaguro.

Year		Cropping pattern	Main stem length (cm)		Main stem node number		Branch number		Pod number (plant^−1)		Pod weight (g plant^−1)
2010		Mono	43.7	(4.51)	12.5	(0.74)	11.1	(2.58)	55.9	(6.30)	225	(27.6)
		D1	42.0	(2.84)	12.3	(0.41)	9.40	(1.29)	57.7	(2.07)	232	(13.8)
One-way ANOVA		F value	0.100		0.010		0.334		0.074		0.043
		Probability	0.768		0.768		0.594		0.799		0.847
2011		Mono	43.0	(3.58)	12.1	(0.47)	–		69.1^a	(7.11)	229^a	(27.1)
		D1	36.0	(4.03)	11.2	(1.01)	–		30.1^b	(4.03)	99.9^b	(13.1)
		R1	50.8	(2.82)	14.0	(0.88)	–		69.2^a	(9.38)	217^a	(32.8)
One-way ANOVA		F value	4.423		3.118		–		9.031		7.662
		Probability	0.066		0.118		–		0.016*		0.022*
One-way ANOVA	Year	F value	0.015		0.283		–		1.911		0.007
		Probability	0.910		0.622		–		0.239		0.938

The data are means of three replicated plots. The values in parenthesis indicate standard error of mean. The effects of cropping patterns on growth and yield in each year were analyzed by ANOVA. In addition, the difference of yield between each year was analyzed by ANOVA. When ANOVA of cropping patterns in each year was significant, post hoc analyses were conducted using Tukey’s multiple comparison test, with the level of statistical significance taken as p < 0.05.

The symbols of * and ** indicate significant differences at p < 0.05 and p < 0.01 by ANOVA, respectively. The same letters adjacent to the value indicate no significant difference at p < 0.05 according to Tukey’s multiple comparison test.

Table 4. Effects of cropping patterns on the growth and seed yield of Tanbaguro.

Year		Cropping pattern	Main Stem length (cm)		Main stem node number		Branch number		Ripened pod number		Seed number (plant^−1)		Seed weight (g plant^−1)
2009		Mono	–		–		–		–		67.5	(8.22)	50.0^b	(5.03)
		D2	–		–		–		–		53.0	(7.98)	40.2	(4.34)
		R2	–		–		–		–		58.3	(9.71)	48.8^b	(12.6)
One-way ANOVA		F value	–		–		–		–		0.719		0.425
		Probability	–		–		–		–		0.525		0.672
2010		Mono	42.7	(3.06)	11.9	(0.44)	9.13	(0.74)	69.7	(5.46)	81.7	(10.9)	52.6	(7.79)
		D2	42.7	(1.45)	11.8	(0.12)	8.13	(0.29)	69.1	(5.07)	87.7	(9.29)	56.6	(7.69)
One-way ANOVA		F value	3.87 × 10^−4		8.70 × 10^−2		1.573		5.78 × 10^−3		0.175		0.132
		Probability	0.985		0.783		0.278		0.943		0.698		0.735
2011		Mono	47.9^a	(2.34)	14.3^a	(0.47)	10.9^a	(0.82)	77.9^a	(1.54)	101^a	(2.77)	70.5^a	(0.91)
		D2	34.5^b	(4.21)	11.4^a	(0.90)	5.40^b	(1.14)	33.4^b	(7.45)	49.8^b	(12.8)	32.3^b	(8.13)
		R2	48.0^a	(1.77)	14.4^a	(0.74)	13.8^a	(0.88)	73.0^a	(8.84)	86.9^a	(6.68)	62.0^a	(6.68)
One-way ANOVA		F value	6.943		5.471		19.69		13.14		9.645		10.80
		Probability	0.027*		0.044*		2.31 × 10^−4**		6.42 × 10^−4**		0.013*		0.010*
One-way ANOVA	Year	F value	1.824		13.32		2.458		2.105		4.302		4.282
		Probability	0.830		0.022*		0.192		0.221		0.069		0.070

The data are means of three replicated plots. The values in parenthesis indicate standard error of mean. The effects of cropping patterns on growth and yield in each year were analyzed by ANOVA. In addition, the difference of yield between each year was analyzed by ANOVA. When ANOVA of cropping patterns in each year was significant, post hoc analyses were conducted using Tukey’s multiple comparison test, with the level of statistical significance taken as p < 0.05.

The symbols of * and ** indicate significant differences at p < 0.05 and p < 0.01 by ANOVA, respectively. The same letters adjacent to the value indicate no significant difference at p < 0.05 according to Tukey’s multiple comparison test.

Table 5. Relative yield (RY), land equivalent ratio (LER) and competitive ratio (CR) of Kurozukin and Tanbaguro in double cropping and relay intercropping.

Year	Cropping pattern	RY (Kurozukin)	RY (Tanbaguro) (Vegetable soybean)	RY (Tanbaguro) (Seed)	LER	CR (Kurozukin)	CR (Tanbaguro) (Vegetable soybean)	CR (Tanbaguro) (Seed)
2009	D2	1.06	–	0.80	1.87	–	–	–
	R2	1.15	–	0.98	2.13	1.18	–	0.85
2011	D1	1.11	0.44	–	1.55	–	–	–
	D2	0.99	–	0.46	1.45	–	–	–
	R1	1.04	0.95	–	1.99	1.09	0.92	–
	R2	0.96	–	0.88	1.84	1.09	–	0.92

The values of RY and LER in double cropping were calculated using the yield data of mono cropping at optimal sowing period.