Precrops and N-fertilizer impacts on soybean performance in tropical regions of Brazil

Yokoyama, Anderson Hideo; Zucareli, Claudemir; Coelho, Antonio Eduardo; Nogueira, Marco Antonio; Franchini, Julio Cezar; Debiasi, Henrique; Balbinot Junior, Alvadi Antonio

doi:10.4025/actasciagron.v44i1.54650

ABSTRACT.

Precrops have different growth patterns, nitrogen (N) requirements, and production of residues varying in amounts and quality that may affect the N-clycling and the soybean (Glycine max L. Merrill) cropped in succession. This study aimed to evaluate the effect of precrops and N fertilization on soybean performance. An experiment was conducted in Londrina, Paraná State, Brazil, with six precrops treatments: fallow, ruzigrass (Urochloa ruziziensis), showy rattlebox (Crotalaria spectabilis), corn (Zea mays) without or with 80 kg ha⁻¹ of N at topdressing as urea, and wheat (Triticum aestivum). Subplots consisted of two levels of N fertilization at soybean sowing: 0 and 30 kg ha⁻¹ of N as ammonium nitrate at sowing. Urochloa ruziziensis as precrops increased the soybean yield (5,171 kg ha^-1) when compared with corn (4,346 kg ha^-1) and fallow (4,467 kg ha^-1). In 2016/17, N fertilization of soybean with 30 kg ha⁻¹ of N at sowing, although increasing the initial plant growth (745 kg ha^-1 with vs. 662 kg ha^-1 without), impairs nodulation (100 mg pl^-1 with vs. 130 g pl^-1 without) and does not increase grain yield. Oil and protein concentrations in soybean grains are not influenced by precrops and N fertilization at sowing. We found that the use Urochloa ruziziensis as cover crop in soybean precrops is a good recommendation option in tropical regions of Brazil, because increasing the yield of soybean grown in succession. N fertilization at in soybean sowing it should not be recommended even in the presence of a large amount of straw.

Keywords:
Glycine max; no-tillage system; cover crops; growth; oil and protein concentrations in grains; off-season crops

[1] * Author for correspondence. E-mail: coelhoagro7@gmail.com

Remaining straw dry matter (kg ha⁻¹)
Season	Urochloa ruziziensis	Crotalaria spectabilis	Corn 0 N	Corn 80 N	Fallow	Wheat	CV (%)
2016/17	3,430 ab	-	2,462 b	2,764 ab	-	4,753 a	33.8
2017/18	2,902 cd	1,545 d	5,010 ab	6,382 a	-	2,673 cd	23.6
Grain yield (kg ha⁻¹)
2016/17	-	-	4,150	4,655	-	3,650	-
2017/18	-	-	5,988	6,305	-	2,764	-

	V3		R2		R5.3
Treatments	NO₃ ⁻-N (mg kg⁻¹)	NH₄ ⁺-N (mg kg⁻¹)	NO₃ ^-N (mg kg⁻¹)	NH₄ ⁺-N (mg kg⁻¹)	NO₃ ⁻-N (mg kg⁻¹)	NH₄ ⁺-N (mg kg⁻¹)
Urochloa ruziziensis	15.4 ^ns	5.6 ^ns	19.2 ^ns	4.4 ^ns	19.9 ^ns	7.4 ^ns
Crotalaria spectabilis	16.9	5.4	18.2	2.6	18.9	7.0
Corn 0 N	17.7	2.8	17.4	4.7	19.3	7.8
Corn 80 N	14.3	6.4	17.7	4.6	19.2	6.9
Fallow	16.9	12.1	15.4	3.1	18.1	6.5
Wheat	16.9	11.1	15.3	4.4	18.9	6.5
CV (%)	17.0	54.0	17.0	62.9	22.0	19.0
Soybean 0 N	15.3b	6.6 ^ns	16.6 ^ns	4.2 ^ns	19.2 ^ns	6.9 ^ns
Soybean 30 N	17.3a	7.9	17.8	3.7	18.9	7.1
CV (%)	15.1	62.0	16.0	49.9	17.0	24.0
Interaction	ns	ns	ns	Ns	ns	ns

	2016/17					2017/18
Treatments	DEN	SDM	NCS	NAC	LAI	DEN	SDM	LAI
	pl. m^-2	kg ha^-1	%	kg ha^-1	-	pl. m^-2	kg ha^-1	-
Urochloa ruziziensis	31.5 ^ns	712 ab	3.4 ab	24.2 bc	7.9 ^ns	25.9 ^ns	545 ^ns	7.0 ^ns
Crotalaria spectabilis	32.0	630 b	3.5 ab	22.0 c	7.7	24.4	579	6.9
Corn 0 N	32.0	810 a	3.4 ab	27.5 b	7.6	25.1	508	7.2
Corn 80 N	29.6	849 a	3.7 a	31.4 a	7.6	25.5	531	7.2
Fallow	30.6	639 b	3.6 a	23.0 bc	7.6	25.1	451	6.9
Wheat	29.4	579 b	3.2 b	18.5 d	7.8	24.7	476	7.2
CV (%)	11.0	16.4	7.4	12.2	3.5	14.3	34.1	9.0
Soybean 0 N	30.9 ^ns	662 b	3.5 ^ns	23.2 b	7.7 ^ns	245 ^ns	507 ^ns	7.0 ^ns
Soybean 30 N	30.8	745 a	3.5	26.1 a	7.7	258	523	7.1
CV (%)	7.6	19.9	7.1	13.5	3.2	12.5	27.6	8.8
Interaction	ns	ns	ns	ns	Ns	ns	ns	ns

Treatments	NN	NDW	URD
	un. pl^-1	mg pl^-1	µmol g^-1
Urochloa ruziziensis	28.8 ^ns	140 a	21.4 c
Crotalaria spectabilis	26.4	90 b	29.1 ab
Corn 0 N	25.1	111 ab	26.6 ab
Corn 80 N	29.4	120 ab	30.4 a
Fallow	27.1	100 ab	30.6 a
Wheat	29.1	150 a	24.8 bc
CV (%)	22.5	28.3	13.3
Soybean 0 N	29.8 a	130 a	27.3 ^ns
Soybean 30 N	25.6 b	100 b	27.0
CV (%)	25.9	34.3	11.7
Interaction	ns	ns	ns

	2016/17		2017/18
Treatments	PH	FPH	PH	FPH
	cm	cm	cm	cm
Urochloa ruziziensis	106.4 ab	13.0 ab	118.9 ab	18.2 a
Crotalaria spectabilis	106.8 ab	14.0 ab	121.2 a	14.8 b
Corn 0 N	109.8 ab	17.8 a	112.1 b	16.3 ab
Corn 80 N	118.7 a	14.9 ab	116.6 ab	14.9 b
Fallow	110.2 ab	13.3 ab	112.9 b	14.8 b
Wheat	98.4 b	10.4 b	112.3 b	15.1 b
CV (%)	10.1	33.5	4.6	11.7
Soybean 0 N	107.9 ^ns	12.9 ^ns	113.2 b	15.8 ^ns
Soybean 30 N	108.9	14.9	119.1 a	15.6
CV (%)	7.9	46.7	4.2	13.0
Interaction	ns	ns	Ns	ns

Brasil

Brasil

Precrops and N-fertilizer impacts on soybean performance in tropical regions of Brazil

ABSTRACT.

	2016/17					2017/18
Treatments	YLD	OIL	OPD	PRT	PPR	YLD	OIL	OPD	PRT	PPR
	kg ha^-1	%	kg ha^-1	%	kg ha^-1	kg ha^-1	%	kg ha^-1	%	kg ha^-1
Urochloa ruziziensis	4,499 ^ns	22.0 ^ns	993 ^ns	35.7 ^ns	1,608 ^ns	5,171 a	23.6 ^ns	1,218 a	33.4 ^ns	1,726 a
Crotalaria spectabilis	4,321	21.5	930	35.7	1,545	4,639 abc	23.1	1,072 ab	34.2	1,587 ab
Corn 0 N	4,223	21.3	899	35.9	1,516	4,346 c	22.9	998 b	33.8	1,468 b
Corn 80 N	4,345	21.4	930	36.2	1,571	4,430 bc	22.9	1,014 b	34.3	1,522 b
Fallow	4,476	21.9	981	35.2	1,576	4,467 bc	23.1	1,035 b	33.7	1,503 b
Wheat	4,560	21.4	980	35.5	1,617	5,047 ab	22.9	1,159 ab	34.1	1,720 a
CV (%)	6.5	4.5	7.2	2.5	6.9	10.4	4.1	12.0	3.9	9.5
Soybean 0 N	4,379 ^ns	21.6 ^ns	947 ^ns	35.9 ^ns	1,572 ^ns	4,626 ^ns	22.9 ^ns	1,064 ^ns	33.9 ^ns	1,570 ^ns
Soybean 30 N	4,429	21.6	958	35.5	1,572	4,740	23.2	1,101	33.9	1,605
CV (%)	8.1	4.1	10.4	2.4	8.1	8.0	4.1	7.7	3.7	9.8
Interaction	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns

	2016/17			2017/18
Treatments	POD	GPP	TGW	POD	GPP	TGW
	un. pl^-1	un. pod^-1	g	un. pl^-1	un. pod^-1	g
Urochloa ruziziensis	46.7 ^ns	2.3 ^ns	148.0 ab	60.8 a	2.1 ^ns	153.5 ^ns
Crotalaria spectabilis	42.3	2.2	139.0 b	59.7 ab	2.1	143.4
Corn 0 N	44.0	2.4	139.2 b	54.6 b	2.1	141.1
Corn 80 N	41.1	2.1	167.2 a	59.3 ab	2.2	151.4
Fallow	41.9	2.3	145.0 ab	62.1 a	2.1	146.7
Wheat	51.4	2.2	137.5 b	59.0 ab	2.2	155.4
CV (%)	17.6	10.8	12.6	10.9	6.9	7.9
Soybean 0 N	44.5 ^ns	2.3 ^ns	144.1 ^ns	57.9 ^ns	2.1 ^ns	145.7 ^ns
Soybean 30 N	44.6	2.1	147.8	60.6	2.2	151.5
CV (%)	19.8	13.6	9.4	17.6	5.8	7.7
Interaction	ns	ns	ns	ns	Ns	ns