Full Length Research Paper
ABSTRACT
Crop residues' inappropriate management is the main constraint causing the decline in soil fertility and crop yields in Burkina Faso. This study was conducted at the Farako-Bâ Research Station from 2014 to 2019 to assess the effects of crop residue management to improve the sustainability of the cotton-cereal based production systems. The experimental design was complete randomized blocks of Fischer with four replications. Three different crop residue management practices were investigated: (i) Crop residue exportation and conventional tillage (T1); ii) Composted crop residues and conventional tillage (T2); and (iii) Crop residues used for soil mulching and no-tillage (T3). Soil chemical characteristics and crop yields were assessed as parameters in this study. Crop yields were improved by 17 to 34% on maize, from 18 to 38% on cotton and from 6 to 14% on sorghum, respectively, with residues recycled into compost (T2) and residues used for soil mulching (T3) compared to residues exported (T1). Crop residue management and soil tillage technics significantly increased the yields of maize, sorghum, and cotton after the first three years of experimentation. Soil chemical properties were not statistically influenced, except for SOM, nitrogen, and available K content. The highest decrease in soil carbon content induced by crop residue exportation (T1) should not be recommended to farmers.
Key words: Crop residues, tillage, soil fertility, cotton-cereals, yield, Burkina Faso.
INTRODUCTION
The new technologies' adoption in agriculture is based on their agronomic, socio-economic, and ecological advantages for farmers. In sub-Saharan Africa, the principles of conservation agriculture (CA) (minimum tillage, permanent soil cover, and crop rotation) have been adopted for many years. Following these general principles, specific locally relevant practices have been developed on smallholder farms around the world to achieve sustainable intensification (Giller et al., 2015). Minimum or zero tillage has evolved considerably in sub-Saharan Africa and demonstrates many benefits. However, this kind of agriculture is struggling to realize wider adoption despite its advantages highlighted by previous studies (Kanté, 2001; Djamen et al., 2015). Djamen et al. (2015) indicated that CA can be a sustainable intensification method for cropping systems. Though CA adoption increases the workload, their study showed evidence of increasing on-farm incomes. Ensuring farmers' sustainable productivity, including improvement and maintenance of favorable soil chemical properties, is a way to move towards good adoption of CA (Erenstein et al., 2012; Brown et al., 2017). The need to lead farmers away from current conventional practices is growing more urgent as these practices are rapidly degrading soil productivity and eroding the ability to maintain, or decrease, cotton and cereal production systems in sub-Saharan Africa (Ouattara et al., 2011; Obalum et al., 2012; Tully et al., 2015). Sustainable intensification goals will not be achieved with current practices.
Good management of crop residues can improve the sustainability of a production system (Bacye and Boro, 2011; Lemtiri et al., 2016). In this regard, agriculture in Sub-Saharan Africa is largely characterized by inadequate practices (Djamen et al., 2015; Lemtiri et al., 2016). In the farming systems of Burkina Faso, crop residues are mainly exported from the fields to provide animal feed because of insufficient access to quality grazing resources (Bacye, 1993; Bonde, 2007). Returning the crop residues to the soil, instead of exporting them as animal feed, improved the soil's physical, chemical, and biological characteristics. The benefits of this practice include improved soil organic matter (SOM), enhanced stability of aggregates, cation exchange capacity (CEC), and increased available nutrients in the soil (Blanco-Canqui and Lal, 2009). The use of crop residues to produce compost or to protect soil by mulching associated with zero tillage is among the technics recommended for achieving sustainable intensification goals in the Burkina Faso farming system.
In the cotton-growing areas of Burkina Faso, fertilization recommendations are based on the application of both organic and chemical fertilizers. To achieve cotton fertilization, the application of 2000 kg ha-1 per year or 6000 kg ha-1 every 3 years of compost is recommended to maintain soil organic status as well as mineral fertilizers by using NPK+S+B (150-200 kg ha-1) and urea (50 kg ha-1) (Ouattara et al., 2021). In addition to compost use, reducing tillage is also recommended in order to maintain soil structure and hasten SOM improvement (Vian et al., 2009). Another form of CA has subsequently evolved as an approach to direct sowing under a mulch-based management system (DMC). This approach induces biomass production in the fields through the association of cover crops with cereals. However, CA is less widely adopted in cropping systems in sub-Saharan African countries due to the limited information available on its benefits.
The purpose of this study is to determine the effects of crop residue management and tillage practices on crops’ productivity and soil chemical properties to improve the sustainability of cotton-zone production systems.
MATERIALS AND METHODS
Site description
The experiment was conducted at the Farako-Bâ Research Station located in Western Burkina Faso (04º20 W and 11º06 N; 450 m altitude). The climate of the site is sub-Sudanese with an annual rainfall between 767 and 1332 mm for the study period from 2014 to 2019 (Table 1).
According to the FAO classification system, the soil of Farako-Bâ is a Lixisol with 12.90% of sand, 71.20% of silt, and 15.90% of clay. The pH water varied between 5.43 and 5.38, the organic matter from 0.97 to 0.82%, the total P from 118.90 to 109.61 mg kg-1 and the total K from 746.25 to 733.82 mg kg-1, respectively in the 0-10 and 10-20 cm layer depths (Table 2). This soil has a low exchangeable base content (1.54–1.40 cmol+ kg-1 soil) and cation exchange capacity (2.94–3.01 cmol+ kg-1 soil).
Plant material
Three cash crops (maize, sorghum, and cotton) and three cover crops were grown as plant materials in this study. Maize composite variety SR21 was used, with a 95-day cycle length (sowing-maturity) and a potential yield of 5000 kg ha-1, and cotton FK37 was used, with a potential yield of 2500 to 3000 kg ha-1 and a cycle length of 150 days. The variety of sorghum Sariasso 01, with a 120-day cycle length and a potential grain yield of 3000 kg ha-1, was also cultivated. This variety is adapted to low rainfall conditions in the area from 400 to 700 mm (Table 1).
Cover crops used were Brachiaria ruziziensis (Congo Grass), Crotalaria juncea (Sunn Hemp), and Cajanus cajan (Pigeon Pea), with potential dry matter biomass production of 7000, 4500, and 10,000 kg ha-1, respectively. These cover crops were associated with maize and sorghum to improve biomass production in the field (Table 1).
Treatments
The experimental design was complete randomized block with three treatments and four replications. Crop residue management combined with tillage practices studied were treatments defined below:
T1. Exportation of crop residues + Conventional Tillage (CT)
T2. Crop residues composted + Conventional Tillage (CT)
T3. Mulching of the soil (crop residues and cover crop biomass) + No Tillage (NT)
Biomass management (crop residues and cover crop biomass)
After the harvest of each grown cereal crop, the stalks of maize and sorghum are entirely exported from the plots (T1). However, for T2 treatment, cereal crop residues are transformed into compost that is used to fertilize the same plots on which the biomass was produced. The composted biomass quantities (maize or sorghum stalks) depend on the crops grown in the rotation.
On average, 5000 kg ha-1 of compost was used per year. Table 3 shows the chemical characteristics of the composts used. The composts content varied from 36.19 to 45.59 % of organic matter, 1.21 to 1.49 % of nitrogen, 0.28 to 0.39 % of P2O5, 1.23 to 2.70 % of K2O, 2214 to 0.95 to 2.02 % of CaO. The pH of the composts ranged from 7.52 to 9.07. In conventional tillage (CT), sowing is carried out on soil ploughed with oxen to a depth of 15 cm.
For T3 treatment, cover crops are grown in the row spacing of maize (Brachiaria ruziziensis and Cajanus cajan) and sorghum (Brachiaria ruziziensis and Crotalaria juncea) to improve biomass production (Table 1). Total biomass resulting from both cover crops and cereal crop residues is kept in mulch on the plot. Thus, cotton is grown in direct sowing under mulch cropping system (DMC) the next year after cultivation of maize or sorghum, which are also sown with no-tillage of soil. This treatment (T3) corresponds to direct sowing under a mulch cropping system (DMC).
Fertilization and crop protection
Mineral fertilization of maize and sorghum is done at 74N-36P-36K-12S-2B and 44N-27P-27K-9S-1.5B on cotton using NPKSB (14-18-18-6S-1B) applied 15 days after emergence and urea (46% N), at 40 days.
Cotton was protected against pests with indoxacarb (25.5 g ha-1) at 30 and 44 days after emergence, a combination of profenofos (300 g ha-1) + lambdacyhalotrhrine (18 g ha) at 58 and 72 days, and acétamipride (16 g ha-1) and lambda cyhalothrine (15 g ha-1) at 86 and 100 days.
Parameters measured
Crop yields and changes in soil chemical properties at 0–10 cm depth were measured over a six-year period (2014–2019). Soil chemical properties measured included pH, soil organic carbon (SOC), azote (N), phosphorus (P), potassium (K), exchangeable bases (Ca2+, Mg2+, K+, and Na+), cation exchange capacity (CEC), and the saturation rate. The different crop successions depending on the year are presented in Table 1.
The chemical analysis of the soil samples was carried out at the Soil-Water-Plant Laboratory of the Farako-Bâ research center. Soil pH was determined with a standard benchtop pH meter and electrod in a stirred slurry with a soil to distilled water ratio of 1 :2.5. The Walkley-Black (1934) method was used to determine SOC. A conversion factor of 1.724 was applied to SOC to calculate soil organic matter (SOM). The total N was obtained by the Kjeldahl method (Hillebrand et al., 1953). The ratio of C: N is obtained from the ratio of the carbon and nitrogen content of the soil. Total P was measured by open vessel digestion with sulfuric acid and colorimetric determination as per Anderson and Ingram (1989). Soil available P was determined by the method of BRAY 1 (Dickman and Bray, 1940). Total K was measured using a spectrophotometer and exchangeable potassium by the 1N ammonium acetate method at pH 7; magnesium and calcium exchangeable ions by a titrimetric method (Ethylene Diamine Tetra Acetic Acid). The exchangeable bases were obtained by the addition of Ca, Mg, K, and Na to the soil. Saturation rates correspond to the ratio of exchangeable bases and the exchange capacity of cations x 100.
Statistical analysis
Data on crop yields and soil chemical parameters such as organic matter, total N, total P and assimilable P, total K and available K, saturation rate, cation exchange capacity, and pH were collected and analyzed. The analysis of variance and standard deviations was performed using the XLSTAT 2016 version. Also, protected LSD test was employed as a post-hoc analysis for the comparison of the means (α = 0.05) using XLSTAT software.
RESULTS AND DISCUSSION
Soil properties at the beginning of experimentation
In 2014, the chemical attributes of soil (Table 2), particularly the pH water values at 0-10 cm and 10-20 cm layer depths, were 5.43 and 5.38, respectively, indicating that this soil was initially strongly acid according to Bunasols (1989). Previous studies in Farako-Bâ station (Bado, 2002; Koulibaly et al., 2014) revealed the soil acidity, which is mainly due to the ack of organic restitution and the use of mineral fertilizers, as well as the cultivation of the soils and their progressive degradation.
Soil organic matter content was below 1%, while nitrogen values ranged between 0.04% and 0.05%. These low contents in this soil confirm the deficiencies of C and N highlighted by previous studies in most soils of Burkina Faso. These results are similar to those of the studies by Zombré (2006) and Ouandaogo et al. (2016), which indicate that soil organic matter degradation is generally caused by its mineralization and farmers’ low organic restitution. According to Bunasols (1989) and Landon (1991), total phosphorus and potassium levels in the soil are considered "low", while available K values, which vary between 126.97 and 136.52 mg kg-1, are considered "high" (Table 2). Initially, the soil had low exchangeable base reserves and CEC values, indicating a lack of chemical properties. According to Bacye et al. (2019) and Kaboré et al. (2021), inappropriate cultivation practices characterized by lack of restitution, destruction of soil structure and exposure, as well as climatic conditions, lead to a degradation of soil fertility.
Soil properties variation during the experimentation
Soil chemical characteristics variations between 2014 and 2019 (Table 4) revealed a decreasing trend. During this period, the SOM decrease was 22, 25, and 34%, respectively, with T3, T2, and T1 treatments. Crop residue management (compost or soil mulch) reduced soil organic matter losses compared to total residue exports associated with conventional tillage (N'Goran et al., 2012; Traoré et al., 2019). Organic restitutions by compost or mulching of soil, combined with minimum tillage, are important approaches to reduce SOM and nutrient losses from crops. These results confirm the role and importance of organic restitutions (Coulibaly et al., 2020; Bacye et al., 2021). The chemical characteristics of the soil after 6 years of production show that the export of residues associated with conventional tillage increases soil nutrient losses through runoff and leaching, in contrast to soil cover and recycling, which ensure a partial restitution of losses linked to crop exports (Razafimbelo et al., 2006; Ouattara et al., 2018).
The total N content, which was 0.05% in 2014, decreased by 20, 24, and 30%, respectively, with T3, T2, and T1 in 2019 (Table 4). Soil nitrogen losses were reduced by no tillage, soil mulching treatment (T3), and recycling of crop residues into compost (T2), according to Baruah and Baruah (2015). Mulching with leguminous cover crops such as Crotalaria retusa and Cajanus cajan reduced nitrogen losses through erosion and leaching of NO (Smith et al., 1987; Meisinger et al., 1991).
From 2014 to 2019, total P losses were 78.21, 52.06, and 65.75 mg/kg soil, respectively, with T1, T2, and T3 treatments. Residue management practices (recycling and mulching) reduced soil P losses. In contrast to total P, available P levels were improved after 6 years of production with residue export (T1) and recycling of crop residues into compost. Although statistically homogeneous after 6 years of production, the recycling of crop residues into compost or used as mulch provided the best total K (297, 91, and 303.15 mg kg-1 soil) and the available K (15.58 and 31.87 mg kg-1 soil) balances compared to exporting all residues (Dakouo, 1994; Armand et al., 2021). Progressive degradation of organic matter, which is more pronounced in tropical regions, would have contributed to maintaining and improving soil P and K levels.
Although statistically equal in 2016 and 2019, soil exchangeable bases and cation exchange capacity decreased when compared to the original state of the soil in 2014, even if a small reduction in exchangeable bases (11 to 26%) and CEC (17 to 23%), which is more pronounced with mulch (T3) than with residue export (T1), were observed (Table 4). According to Bednarz et al. (1998); FAO (2006), these decreases were linked to soil organic matter levels.
Crop yields variation
Crop residue management (mulch and compost) improved crop yields significantly from the fourth year of production (Table 5). These yield increases related to organic restitution in the form of compost or mulch are in the order of 18-38% on cotton yield, 6–14% on sorghum yield, and 17–34% on maize yield, respectively, with residue recycling in compost (T2) and soil cover under mulch (T3) compared to residue export (T1) (Koulibaly et al., 2016; Traore et al., 2021; Nyagorme et al., 2021).
CONCLUSION
This study showed the benefits of organic restitution in any form influence crop yields and soil chemical properties. Like the recycling of crop residues into compost, the production of biomass by combining cover crops with cereals and using them as a soil cover reduces soil nutrient losses. This practice, which is a faithful reflection of cover cropping systems, needs to be further explored in order to offer producers an alternative for sustainable soil fertility management.
CONFLICT OF INTERESTS
The author has not declared any conflict of interests.
REFERENCES
Anderson JM, Ingram JSI (1989). Tropical soil biology and fertility: A handbook of methods. CAB International, Wallingford, Oxfordshire 221. |
|
Armand ND, Fosah MR, Oscar WF, Bruno NB, Duthie TV, Nyemene KPJ, Carnot AC, Désiré TV (2021). Evaluation of soils fertility, growth, nutrient uptake and yield traits of peanut under indigenous and effective microorganism fertilizers in sandy ferralitic soils in Douala, Cameroon. African Journal of Agricultural Research 17(3):432-441. |
|
Bacye B (1993). Influence des systèmes de culture sur le statut organique et minéral des sols ferrugineux et hydromorphes de la zone soudano-sahélienne. Thèse de docteur de l'Université d'Aix-Marseille III. ORSTOM, Montpellier, France, p. 243. |
|
Bacye B, Boro A (2011). Study of Organic Matter Flows on Farms in the Western Cotton Zone of Burkina Faso. Tropicultura 29(3):148-152. |
|
Bacye B, Kambire HS, Sawadogo MO, Zonga AM (2021). Effets des modes de gestion des résidus du bananier et d'options de fumure minérale sur le rendement du maïs et les caractéristiques chimiques du sol dans un système de rotation bananier /maïs à l'Ouest du Burkina Faso. International Journal of Biological and Chemical Sciences, 15(3): 1208-1221. |
|
Bacye B, Kambire HS, Some AS (2019). Effets des pratiques paysannes de fertilisation sur les caractéristiques chimiques d'un sol ferrugineux tropical lessivé en zone cotonnière à l'Ouest du Burkina Faso. International Journal of Biological and Chemical Sciences 13(6):2930-2941. |
|
Baruah A, Baruah KK (2015). Organic Manures and Crop Residues as Fertilizer Substitutes: Impact on Nitrous Oxide Emission, Plant Growth and Grain Yield in Pre-Monsoon Rice Cropping System. Journal of Environmental Protection 6 :755-770. |
|
Bednarz CW, Oosterhuis DM, Evans RD (1998). Leaf photosynthesis and carbon isotope discrimination of cotton in response to potassium deficiency. Environmental and Experimental Botany 39:131-139. |
|
Blanco-Canqui H, Lal R (2009). Corn stover removal for expanded uses reduces soil fertility and structural stability. Soil Science Society of America Journal, (73):418-426. |
|
Bonde D (2007). Effets des modes de gestion de la fertilité sur les exportations des cultures dans la rotation coton-maïs-sorgho. Mémoire d'Ingénieur du Développement Rural, Université Polytechnique de Bobo Dioulasso, Burkina Faso, p. 50. |
|
Brown B, Nuberg I, Llewellyn R (2017). Negative evaluation of conservation agriculture: perspectives from African smallholder farmers. International Journal of Agricultural Sustainability 15(4):467-481. |
|
Bunasols (Bureau national des sols) (1989). Liste des études pédologiques réalisées au Burkina Faso depuis 1955. Doc. Techn. N° 4, Bunasols, Ouagadougou, p. 56. |
|
Coulibaly SS, Touré M, Kouamé AE, Kambou IC, Soro SY, Yéo KI, Koné S (2020). Incorporation of Crop Residues into Soil: A Practice to Improve Soil Chemical Properties. Agricultural Sciences 11:1186-1198. |
|
Dakouo D (1994). Les carences en potassium sur cotonnier (Gossypium hursitum L) dans les systèmes de culture : cs de la zone cotonnière Ouest du Burkina Faso. Thèse de docteur-ingénieur, Université Nationale de Côte d'Ivoire, p. 161. |
|
Dickman SR, Bray HR (1940). Colorimetric Determination of Phosphate. Industrial and Engineering Chemistry Analytical Edition 12:665-668. |
|
Djamen NP, Andrieu N, Zerbo I, Ouédraogo Y, Le Gal PY (2015). Agriculture de conservation et performances des exploitations agricoles en Afrique de l'Ouest. Cahier Agriculture 24:113-22. |
|
Erenstein O, Sayre K., Wall P, Hellin J, Dixon J (2012). Conservation agriculture in maize- and wheat-based systems in the (sub) tropics: Lessons from adaptation initiatives in South Asia, Mexico, and Southern Africa. Journal of Sustainable Agriculture 36(2):180-206. |
|
FAO (2006). Sécurité alimentaire et développement agricole en Afrique Subsaharienne. Documentation FAO. |
|
Giller KE, Andersson JA, Corbeels M (2015). Beyond conservation agriculture. Frontiers in Plant Sciences 6:1-14. |
|
Hillebrand WF, Lundell GEF, Bright HA, Hoffman JI (1953). Applied Inorganic Analysis. John Wiley, Sons, Inc: New York, USA, P. 1034. |
|
Kaboré F, Zongo GH, Dogbey BF, Ouattara K, Millogo Y, Kaboré L, Hien E, Zombré PN (2021). Implications of Non-Carbonate Dolomite Minerals in the Formation of Red Soils in a Paleokarstic Context in the Taoudeni Basin in Burkina Faso. Open Journal of Soil Science 11:59-71. |
|
Kanté S (2001). Gestion de la fertilité des sols par classe d'exploitation au Mali-Sud. Tropical Resource Management Papers, No. 38; published as thesis, Wageningen University P. 243. |
|
Koulibaly B, Dakuo D, Traoré K, Ouattara A, Ouattara K, Traoré O (2016). Soil tillage practices and crops rotations effects on yields and chemical properties of a lixisol in Burkina Faso. Journal of Applied Biosciences 106:10320-10332. |
|
Koulibaly B, Traore O, Dakuo D, Lalsaga R, Lompo F, Zombré PN (2014). Acidification des sols ferrugineux et ferrallitiques dans les systèmes de production cotonnière au Burkina Faso. International Journal of Biological and Chemical Sciences 8(6):2879-2890. |
|
Landon JR (1991). Booker Tropical Soil Manual. A Handbook for Soil Survey and Agricultural Land Evaluation in the Tropics and Subtropics. Oxon, Booker Tate Limited; Harlow, Essex: UK, Longman, p. 474. |
|
Lemtiri A, Degrune F, Barbieux S, Hiel MP, Chélin M, Parvin N, Vandenbol M, Francis F, Colinet G (2016). Crop residue management in arable cropping systems under temperate climate. Part1 : Soil biological and chemical (phosphorus and nitrogen) properties. Biotechnologie, Agronomie, Société et Environnement S1:236-244. |
|
Meisinger JJ, Hargrove WL, Mikkelsen RL, Williams JR, Benson VW (1991). Effects of cover crops on groundwater quality. In Cover Crop for Clean Water; Hargrove, W.L., ed.; Soil and Water Conservation Society: Ankeny, Iowa, pp. 9-11. |
|
N'Goran KE, Kassin KE, Zohouri GP, Yoro GR (2012). Gestion améliorée de la jachère dans le système de culture à base d'igname par l'utilisation de légumineuse de couverture. Journal of Applied Biosciences 52:3716-3724. |
|
Nyagorme DKA, Amoah AA, Adjei-Gyapong T (2021). Response of maize (Zea mays L.) to foliar and soil applied fertilizers in the Semi-deciduous forest zone of Ghana. African Journal of Agricultural Research 17(8):1114-1122. |
|
Obalum SE, Buri MM, Nwite JC, Watanabe Y, Igwe CA, Wakatsuki T (2012). Soil degradation-induced decline in productivity of sub-Saharan African soils: the prospects of looking downwards the lowlands with the Sawah ecotechnology. Applied and Environmental Soil Science 2012. |
|
Ouandaogo N, Ouattara B, Pouya MB, Gnankambary Z, Nacro HB, Sedogo PM (2016). Effets des fumures organo-minérales et des rotations culturales sur la qualité des sols. International Journal of Biological and Chemical Sciences 10(2):904-918. |
|
Ouattara A, Koulibaly B, Dakouo D, Coulibaly K, Bazongo P, Traore O, Nacro HB (2021). Effects of Direct Sowing under Mulch-Based Cropping System (DMC) on Cotton and Maize Yield and Chemical Characteristics of Ferruginous Soil (Lixisoil) In the South Sudan Area of Burkina Faso. Open Journal of Soil Science 11:352-365. |
|
Ouattara B, Coulibaly K, Kohio E, Doumbia S, Ouédraogo S, Nacro HB (2018). Effets du Système de Culture sous couverture Végétale (SCV) sur les flux hydriques d'un sol ferrugineux à l'Ouest du Burkina Faso. International Journal of Biological and Chemical Sciences 12(4):1770-1783. |
|
Ouattara B, Ouattara K, Lompo F, Yao-Kouame A, Sedogo PM (2011). De la culture itinérante à la culture permanente : impact sur le statut organique et l'agrégation d'un lixisol ferrique à l'Ouest du Burkina Faso. Agronomie Africaine 23(1):1-9. |
|
Razafimbelo TM, Albrecht A, Basile I, Borschneck D, Bourgeon G, Feller C, Ferrer H, Michellon R, Moussa N, Muller B, Razanamparany C, Seguy L, Swarc M, Oliver R (2006). Effet de différents systèmes de culture à couverture végétale sur le stockage du carbone dans un sol argileux des Hautes Terres de Madagascar. Etude et Gestion des Sols 2(13):113-127. |
|
Smith MS, Frye WW, Varco JJ (1987). Legume winter cover crops. Advances in Soil Science 7: 95-139. |
|
Traore A, Yameogo LP, Djindiere O, Traore K, Bazongo P, Traore O (2021). Effets comparés du tourteau de neem [Azadirachta indica (A. Juss)] et du compost sur le rendement du sorgho [Sorghum bicolor (L. Moench)] en zone Sud- soudanienne du Burkina Faso. Journal of Applied Biosciences 163:16834-16845. |
|
Traoré M, Koulibaly B, Pousga S, Kambou A, Ouédraogo S, Coulibaly K, Nacro HB (2019). Variation of carbon and major nutrients contents in two types of soil under stone bunds management in cotton-based cropping systems in the Sudanese zone of Burkina Faso. International Journal of Environment, Agriculture and Biotechnology 6(4):1896-1904. |
|
Tully K, Sullivan C, Weil R, Sanchez P (2015). The state of soil degradation in Sub-Saharan Africa: Baselines, trajectories, and solutions. Sustainability 7(6):6523-6552. |
|
Vian JF, Peigné J, Chaussod R, Roger-Estrade J (2009). Effets du mode de travail du sol sur les microorganismes à l'échelle du profil cultural. Étude et Gestion des Sols 16 (¾):355-364. |
|
Walkley A, Black RN (1934). An examination of the method Dedtjareff for determining soil organic matter and to proposed modification of the chromic acid titration method. Soil Science 37:29-38. |
|
XLSTAT (2016). CATA data analysis, |
|
Zombré NP (2006). Variation de l'activité biologique dans les zippella (sols nus) en zone subsahélienne du Burkina Faso et impact de la technique du Zaï (techniques des poquets). Biotechnologie, Agronomie, Société et Environnement 10(2):139-148. |
Copyright © 2024 Author(s) retain the copyright of this article.
This article is published under the terms of the Creative Commons Attribution License 4.0