Objective: The long-term impacts of conventional tillage through compaction, soil erosion and loss of soil fertility have led to evaluation of this system. To mitigate these problems, simplified cultivation techniques (SCT) are increasingly practiced. The objective of this review is to clarify the effects of conventional tillage and minimum tillage on soil fertility. Methodology and Results: The methodology is based on a documentary research through a synthesis and a confrontation of the researches results of different authors. It is found that, after 5 to 6 years, conventional tillage lowers the fertility of the soil and reduces its productivity. There is a diversity of SCT with convincing results. These techniques leave more agricultural residues and allow an improvement of the indicator of organic matter on the soil by reduction of the mineralization. The STC, such as zero tillage, increase soil fertility and have the potential to reduce greenhouse gas emissions. Improving soil fertility increases yield with a saving in working time. Hydraulic conductivity increases when switching from conventional tillage to direct sowing. Compared to conventional tillage, SCT provide an ideal environment for soil fertility recovery. However, the adoption of SCT and no-till is subject to a constraint on the agricultural equipment used. The design of effective equipment remains the challenge to facilitate large-scale application of SCT. Conclusion and application of results: It is noticed that conventional tillage induce long-term disturbance of soil properties and reduce fertility. Simplified cultivation techniques and particularly a direct sowing have a positive effect on the amount of soil organic matter, its density and water retention, and final production. The specific direct seeder must be designed to accompany the mechanization of these techniques.

The deep assessment of agricultural mechanization inside developing countries could help for local action-taking. This study investigates the use of tractors between the poles of agricultural development (PAD) in Benin Republic. Using a multi-stage random sampling procedure and a questionnaire, 203 tractor users were surveyed in 43 municipalities distributed across the seven PADs of the country. Kruskal-Wallis tests were carried out to compare the different poles of agricultural development based on the mechanization level and tractor performances. Student-Newman-Keuls tests were used to structure the means of these variables. The results show a significant variation (P < 0.05) of the mechanization level between the PADs. Apart PAD1, all the poles use greater than 60 % manual equipment. Animal-drawn is most implemented in the northern part of the country (PAD1; 2 and 3). The use of tractors is lower over the country, and the PAD2 and PAD3 are the most users. From PAD4 to PAD7, the combination of manual tillage with animal power or tractor is not well represented, indicating manual tillagebased agriculture in these poles. In general, 53.20% of the users do not have a tractor parking and the repair center is quasi-absent (97.54 %). PAD2; 4 and 3 are most disc plow users. Mechanical sowing is more observed in PAD2 and 7 and absent in PAD1; 3 and 4. Moreover, the harvester is present in PAD2; 4; 6, and 7. On average, the highest mechanized area was 134.56 ha from PAD3, whereas, the lowest, 12.00 ha was found in PAD7. PAD7 spends more on plowing (47670 FCFA) than the other poles. The mechanized plowing is most slower in PAD7 (3.53 h/ha) while much faster at the PAD2 (1.96 h/ha). These results could help decision-makers for accurate actions taking to advocate for agricultural mechanization sectors in the country based on the weakness of each pole of agricultural development.

In order to design a seeder for direct sowing, a seed characterization study was conducted. The objective was to assess the physical, mechanical and kinetic properties of the most cultivated cereals and leguminous in Benin. Two varieties of Zea mays, four varieties of Vigna unguiculata, one variety of Arachis hypogea, one variety of Cajanus cajan and two varieties of Glycine maxwere studied. It was noticeda variation in physical parameters not only between species but also between varieties of the same species. All sphericity coefficients are greater than 0.7 with C.cajan which is more spherical (0.91±0.03) against the DMR ESR-W/QPM and 85 TZSR-W varieties of Z.mays which are the least spherical with 0.72±0.10 and 0.71±0.11 respectively. The rupture force generally increased from 14 to 720 N. Vigna TVX 32-36 is the most resistant with 633.3±75.72 N against 16.0±2.0 N for Arachis TS32-1 the least resistant. Overall, the falling speed decreased from 1.67 to 0 m/s on the rigid PVC, from 1.36 to 0 m/s on the black plate and from 1.67 to 0 m/s on the transparent hose when the angle of inclination increases from 20° to 70°r elative to vertical. These parameters are essential for good sizing of the distribution system and the seed descent channels for a seeder.They can also be used for grains calibration and other use in agricultural engineering and food processing.

The physical properties of soils are important for proper monitoring of soil functions. In order to evaluate soil resistance to agricultural equipment, a study was carried out on the four main soil types (ferralitic, ferruginous, hydromorphic and vertisol) in the eight agroecological zones of Benin. The objective of this work was to determine the physical and mechanical parameters of the soils. A sampling of soil types by agroecological zone was carried out in 36 localities in Benin to record vertical and horizontal soil strengths using a compactometer and a penetrometer. These data were complemented by measurements of texture, density and water content of the soil samples. An analysis of variance, polynomial regressions and Pearson correlation were performed between the parameters studied. It is noted that majority of soils assessed were sandy loam. The high sand content in most soils would be due to the depth considered (20 cm). The bulk densities range from 1.21 to 1.73gcm-3 and water contents from 4.9 to 35.11%. Vertical resistances range from 3.89 to 16.36 kg cm-2 and horizontal resistances from 1.03 to 4.44 kg cm-2. Strong soil resistances (vertical and horizontal) are recorded in the northern part of Benin where large proportions of the gravelswere observed in the samples taken. A positive correlation was observed between vertical resistance and horizontal soil resistance. It can be concluded that soil resistance in Benin vary from one agro-ecological zone to another, but the linking of soil properties is less significant between zones.

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