Cotton (<i>Gossypium hirsirtum</i> L.) production under an organic crop rotation system and weather vagaries in the humid tropics

Oluwaseun E. Ijaodola; Victor I. O. Olowe; John A. Oyedepo; Ololade A. Enikuomehin; Chris. O. Adejuyigbe; Joy N. Odedina; Oluwaseun E. Ijaodola; Victor I. O. Olowe; John A. Oyedepo; Ololade A. Enikuomehin; Chris. O. Adejuyigbe; Joy N. Odedina

doi:10.48130/tia-0024-0033

Figures (3) Tables (6)

Figure 1.
Map of the experimental plots at the Federal University of Agriculture, Abeokuta, Nigeria.
Figure 2.
Monthly rainfall distribution and mean temperature during the experimental periods (July−November 2019 and 2020) and the long-term (1985−2019) at the Federal University of Agriculture Abeokuta, Nigeria.
Figure 3.
The coefficient of variation of rainfall during the growing season in Nigeria for three decades.

Soil composition	Continuous cropping (−OF) (CS1)	Continuous cropping (+OF) (CS2)	Rotation (+OF) (CS3)	Rotation (−OF) (CS4)	Conventional (CS5)
Mechanical composition (g/kg)
Clay	65	85	85	85	65
Silt	35	45	45	25	65
Sand	900	870	870	890	870
Textural classification	Sand	Loamy sand	Loamy sand	Loamy sand	Loamy sand
pH	6.6	6.9	6.5	6.9	6.8
Total N (g/kg)	0.97	0.94	0.77	0.84	0.59
OC (g/kg)	9.5	5.4	10.4	8.4	13.4
P (mg/kg)	2.56	4.87	23.59	3.01	3.64
Exchangeable cation (cmol/kg)
K	0.12	0.06	0.08	0.09	0.12
Ca	3.89	2.89	2.99	3.39	4.59
Mg	1.74	1.48	1.63	1.96	1.81
Na	0.49	0.34	0.39	0.30	0.59
Micronutrient (mg/kg)
Mn	264	280	356	288	299
Fe	12	12	12	10	14
Zn	51	54	51	52	51
OC: organic carbon.

Table 1.

Pre-cropping physical and chemical properties of the soil in 2019.

Soil composition	Continuous cropping (−OF) (CS1)	Continuous cropping (+OF) (CS2)	Rotation (+OF) (CS3)	Rotation (−OF) (CS4)	Conventional (CS5)
Mechanical composition (g/kg)
Clay	37.8	1.00	16.1	19.0	18.0
Silt	40.5	149.8	100	151.1	163.5
Sand	958.5	833.7	879.3	834.3	798.7
Textural classification	Sand	Loamy sand	Loamy sand	Loamy sand	Loamy sand
pH	7.3	7.4	7.3	7.4	7.2
Total N (g/kg)	0.82	0.53	0.87	0.81	0.92
OC (g/kg)	9.6	6.2	10.2	9.4	10.6
P (mg/kg)	35.68	45.42	37.51	61.86	40.55
Exchangeable cation (cmol/kg)
K	0.34	0.36	0.69	0.41	0.36
Ca	0.98	1.52	2.29	1.68	1.51
Mg	1.04	1.08	1.79	1.21	1.13
Na	0.17	0.18	0.29	0.18	0.18
Micronutrient (mg/kg)
Mn	4.29	4.68	7.35	4.52	4.20
Fe	9.10	10.22	10.70	7.35	8.00
Zn	5.61	7.23	9.69	7.28	6.81
OC: organic carbon.

Table 2.

Pre-cropping physical and chemical properties of the experimental site in 2020.

Parameters	July		Aug		Sept		Oct		Nov		Total		Long term rainfall
Parameters	2019	2020	2019	2020	2019	2020	2019	2020	2019	2020	2019	2020	35 years
Mean temperature (°C)	26.2	25.7	26.5	26.2	26.6	26.1	26.4	27.1	27.9	28.3	141.2	133.4	−
Total rainfall (mm)	108.7	109.5	65.8	2.9	96.3	246.31	310	127.6	112.3	7.0	693.1	493.3	632.8
Number of rainy days	11	8	8	1	10	11	19	11	5	1	53	32	−
Relative humidity (%)	87.4	82.5	83.4	80.0	85.7	79.0	84.0	71.8	86.9	69.1	427.4	382.4	−
Sunshine (h)	2.2	2.3	2.5	3.2	2.0	2.9	1.7	3.8	5.2	5.5	13.6	17.7	−
Source: Department of Agro Meteorology and Water Management, Federal University of Agriculture, Abeokuta, Nigeria.

Table 3.

Some weather parameters during the late cropping season (July–November) in 2019 and 2020.

AEZs	1991−2000		2001−2010		2011−2020
AEZs	MAnRD	MAnDD	MAnRD	MAnDD	MAnRD	MAnDD
AS	56.2	309.1	56.9	308.3	58.6	306.7
SA	83.1	282.2	84.3	280.9	84.9	280.4
NGS	107.1	258.2	106.9	258.3	107.8	257.5
SGS	115.1	250.2	114.1	251.1	115.2	250.1
HA	184	181.3	177.7	187.5	181.6	183.7
MA	138.4	226.9	135.8	229.4	139.5	225.8
DS	127.5	237.8	127.8	237.4	129.1	236.2
HF	161	204.3	162.3	202.9	167.4	197.9
AS: Arid/Sahel; SA: Semi-Arid; NGS: Northern Guinea Savanna; SGS: Southern Guinea Savanna; HA: High Altitude; MA: Mid Altitude; DS: Derived Savanna; HF: Humid Forest; MAnDD: Mean Annual Dry Days; MAnRD: Mean Annual Rainy Days.

Table 4.

Mean annual rainy days (MAnRD) and Mean annual dry days (MAnDD) in the agroecological zones (AEZs) from 1991 to 2020.

Cropping system	2019					2020
Cropping system	PHTMAT (cm)	NSYPB per plant	NMONB	NTBR	NBOLLS	PHTMAT (cm)	NSYPB per plant	NMONB	NTBR	NBOLLS
CS1	86.1^a	11.4^c	1.1^a	12.5^c	13.6^c	54.8^c	12.6^c	0.4^a	13.0^a	9.1^c
CS2	109.6^a	14.7^ab	1.0^a	15.8^b	24.3^a	79.6^ab	15.7^ab	0.7^a	16.4^a	11.7^bc
CS3	109.1^a	14.3^b	1.5^a	15.8^b	24.2^a	85.9^a	15.6^ab	1.3^a	16.9^a	17.6^a
CS4	105.3^a	14.0^b	1.5^a	15.5^b	22.3^ab	67.0^bc	14.7^b	0.6^a	15.3^a	9.8^c
CS5	113.1^a	16.9^a	2.3^a	19.2^a	21.2^b	87.0^a	17.0^a	1.5^a	18.6^a	13.5^b
LSD 5%	ns	2.28	ns	2.26	2.26	16.90	1.98	ns	ns	2.90
CS1 - Continuous cropping (without organic fertilizer), CS2 - Continuous cropping (with organic fertilizer), CS3 - Rotation (with organic fertilizer), CS4 - Rotation (without organic fertilizer) and CS5 - Conventional system (60 kg N, 56 kg P₂O₅ and 60 kg K₂O, and herbicide), ns: not significant, LSD: least significant difference, PHTMAT: Plant height at maturity, NSYPB: Number of synpodia branches, NMONB: number of monopodia branches, NTBR: number of total branches, NBOLLS: Number of bolls. Means followed by the same alphabeths are not significantly different from each other based on the leaset significance difference test at 5% probability level.

Table 5.

Effects of cropping system on plant height (cm) at maturity, number of synpodia, monopodia, and total branches of plant, and bolls per plant in 2019 and 2020.

Cropping system	2019				2020
Cropping system	SCWT	WTSEEDS	WTLINT	SCYD	SCWT	WTSEEDS	WTLINT	SCYD
CS1	7.3^a	5.3^b	2.0^a	204.96^b	8.6^b	6.3^c	2.5^c	230.44^c
CS2	22.5^a	16.0^a	6.4^a	631.95^a	19.3^a	12.1^b	6.4^b	541.80^b
CS3	24.1^a	18.9^a	5.1^a	675.08^a	25.7^a	18.1^a	8.2^ab	692.16^ab
CS4	24.2^a	19.3^a	4.8^a	677.88^a	28.0^a	20.1^a	9.3^a	784.56^a
CS5	11.3^a	5.8^b	5.5^a	318.40^b	9.7^b	5.8^c	3.2^c	272.72^c
LSD 5%	4.35	3.75	ns	122.048	7.90	4.06	2.55	207.380
CS1 - Continuous cropping (without organic fertilizer), CS2 - Continuous cropping (with Organic fertilizer), CS3 - Rotation (with Organic fertilizer), CS4 - Rotation (without organic fertilizer) and CS5 - Conventional system (60 kg N, 56 kg P2O5 and 60 kg K2O, and herbicide), ns: not significant, LSD: least significant difference, SCWT: Seed cotton weight, WTSEEDS: Weight of seeds, WTLINT: Weight of lint, SCYD: Seed cotton yield. Means followed by the same alphabeths are not significantly different from each other based on the leaset significance difference test at 5% probability level.

Table 6.

Effects of cropping system on seed cotton weight (g), weight of seeds (g), weight of lint (g), and seed cotton yield (kg/ha) in 2019 and 2020.