In this context sometimes antibiotics are administered prophylactically in intensive livestock farming.This is not standard in organic farming with the result that in the first days of post-weaning the weight gain declines or stagnates completely. Not until after coming through that period piglets show an increased weight gain,what corresponds with the point of intersection of the two straight lines of the model at an age of about 50 days.In contrast to De Behr , who described a step-wise linear growth model for Belgian Blue cattle less than 20month of age, the point of intersection was not fixed in advance, but it was determined from the growth data only through the goodness of fit. Water and soil are important natural resources that play a prominent role in domestic activities and agricultural development in most African cities, the pressure on the use of these resources is constantly increasing due to the exponential increase of the population orchestrated by rural exodus.

In this situation,the design of food stuff supply is modified in urban and peri-urban areas of Yaounde in Cameroon nft hydroponic system. Vegetables are valued by the population; therefore vegetable farming is not only a source of food supply but also a source of employment in agricultural sector . This activity is mainly located in swampy lowlands, slopes, roadsides with heavy pressure on space . Vegetable farming reveals an interaction among the categories of actors, spaces types, crops species,the products obtained and the average incomes generated . It thus constitutes one of the main economic activities on which the population depends. This type of agriculture is demanding in terms of soil fertility management and water supply. There is a significant investment in crop techniques, fertilizers used, and pesticides treatments to meet the ever-increasing demand throughout the year.The increasing demand for vegetable produces leads to an intensification of their production  aiming to high yields, which may negatively impact the preservation of water and soil resources . This study aimed at having a better knowledge of the characteristics of the vegetable farming in Yaounde, Cameroon. The study was carried out in July 2016 at the Nkolbisson and Nkolondom III peri-urban vegetable farming sites,West and North of Yaounde respectively .

Yaounde, the capital of Cameroon enjoys a rolling topography with dominant slope between 10 and18%. Steeper slopes  occur locally whereas flatter tracts of land are found on small plateaus. The average annual rainfall among to 1600 mm and occurs in a bimodal configuration such that the first and second cropping seasons,separated by a 4-month dry season, last from mid-March to early July and from late August through mid-November respectively . 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 inter tropical 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 surveys were conducted during the month of July 2016 by using semi-structured questionnaires as described by Sinarinzi and Nisabw . A total of100 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,hydroponic nft system 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.