The duration of each of these seasons varies today and the rains in the second season are erratic due to global warming. The population of Yaounde was estimated in 2015 at 2.8 million . The intertropical type of vegetation is observed in Yaounde with a predominance of humid forest. The city’s hydrographic network is very diverse and consists mostly of streams, rivers and ponds. Apart from the hydromorphic soils located in the wetland, ferralitic soils predominate with good physical properties with internal drainage and good water retention capacity. These soils are acid with a low cation exchange capacity . The lithological bedrock is essentially formed by the grenating gneisses.The surveys were conducted during the month of July 2016 by using semistructured questionnaires as described by Sinarinzi and Nisabw . A total of 100 permanent or seasonal farmers were surveyed with 50 interviewers per site.

Using the knowledge of local residents who have been working on vegetable farming, list of all farmers in each village was generated. To select farmers, a cluster sampling strategy was adopted. Using this list as sampling frame, households were selected in each site using a simple random sampling technique . The households were sorted using the random numbers from lowest to highest and the first 50 households were used as the sample. The data collected concerned the socio-economic characteristics of the farmers , the area and number of years of farming in the site, cultural practices associated with crop production and the training of farmers on the appropriate use of pesticides and water.Irrespective of the site, survey results show that farmers are grouped into four classes according to their level of education . There was vegetable farming with no formal education , others with primary, or secondary or university levels. Literate farmers accounted for the smallest proportion , while those with secondary education constituted the largest proportion in both sites. However it is worth noting, that 20 and 38% of farmers at Nkolbisson and Nkolondom III respectively , have attained a university study level and therefore practice this activity on a seasonal basis. In general, the percentage of vegetable farming with at least a secondary school level is higher in Nkolbisson as compared with Nkolondom III .In the both vegetable farming sites, there are four main classes of specific training: general education and technical education, agriculture and livestock .

In Nkolondom III, there exist a high proportion of vegetable farming with training in animal husbandry , while in Nkolbisson, those with technical education constitute the highest proportion. To sum up, the percentage of vegetable farming with specific training in agriculture is low in both sites: 22% in Nkolbisson and 28% in Nkolondom III whit a difference of 6% between them.Different levels of pressure were observed on the soils of Nkolbisson and Nkolondom III. The frequency of farming exploitation of these soils at Nkolbisson varies according to the number of years they have been cultivated and the area occupied. It decreases drastically by 30% to 5%. Plots under cultivation between 1 and 15 years are heavily exploited compared to those of over 16 years of cultivation . The same holds true for Nkolondom III where the frequency of farming of these plots also varies according to the number of years under use. The decrease was drastic in the other of 52.4% to 2.4%. Similarly, soils under cultivation between 1 and 5 years are heavily exploited compared with those of over 6 years of used . The over farming of soils is more observed on plots under cultivation between 1 and 15 years at Nkolbisson , whereas at Nkolondom III, it happens on plots between 1 and 5 years old . On the other hand, the over exploitation is low on plot with more than 16 years under cultivation in both sites. The percentage of over exploitation soils under cultivation between 1 and 5 years is 22.4% higher at Nkolondom III than Nkolbisson site. In the contrary, this over activity is lower by 2.6% in Nkolondom III as compare to Nkolbisson in plots over 26 years under cultivation.

The fertilizers and amendments used in the Nkolbisson and Nkolondom III vegetable farming were mostly chicken manure, crop residues, pig slurry and compound chemical fertilizer NPK. During these surveys, it appeared that farmersderived the level of fertility from the time under cultivation. These farmers therefore apply fertilizers according to the age of the plots. That is, the older the plot , the more fertilizers it receives. Moreover, the quality of these fertilizers also varies according to the duration of exploitation.There is a greater use of inputs on older farms . The rate of chicken manure applied on plots of more than 26 years old changed from simple to triple as compared to the one applied on younger plots with rates of 20% to 59% and 12% to 34% respectively in Nkolbisson and Nkolondom III. Therefore there is an increase of 8% and 29% from young to old plots respectively in Nkolbisson and Nkolondom III.