COMPROBACIÓN DE HIPÓTESIS

The importance of crops cultivated in town for subsistence purposes is obvious. Maize and rice were of particular relevance in Morogoro and maize and beans in Mbeya because ‘they are staple foods in this town’ as many respondents in the in-depth survey said. Also important were vegetables (amaranth or mchicha in particular) in both towns, cassava in Morogoro and Irish potatoes in Mbeya. However, most crop-cultivating households cannot consume their crops through- out the year, either because the produce is insufficient or because of a lack of storage facilities. Most households indicated that, especially during harvesting, their crop-cultivating activities were helpful in solving food problems, although several respondents in Morogoro said that they benefited from them at all times of the year.

An attempt has been made to estimate the contribution of the major staple foods produced by the urban crop cultivators to the households’ energy require- ments. The underlying idea is that a certain number of kilocalories are required on a daily basis to maintain the human body, and the question is how many of these are produced in urban gardens. For this purpose, a calculation was made of the aggregate energy yield produced by urban farming and the total energy needs of the urban population. It should be pointed out that the population’s diet is not based only on the crops investigated in this study; thus the remaining kilocalories need to be derived from other crops and from livestock. Moreover, this calcula- tion refers only to direct consumption needs and not to other human needs. At the outset, a number of assumptions were made:

1. Daily human needs are assumed to be 2,200 kcal, a figure that presents an

average that cancels out differences in age, weight and consumption pat- terns.

2. The energy yield of every kg of production of a specific crop is similar

regardless of the quality of the produce.

3. The total production represents an annual average yield. There is no annual variance.

4. There are, on average, 5.4 and 6.1 persons per household in Morogoro and

Mbeya, respectively (see Chapter 3).

A number of variables must be incorporated in the assessment. First, there are those related to levels of production, or the output per crop. Second, food-gener- ating activities may dominate urban agricultural production but there are addi- tional forms of social production (giving away food) and commercial production. Differential estimates are therefore required according to different levels of self- consumption. Tables 6.2a (Morogoro) and 6.2b (Mbeya) present the calculation procedure incorporating the different steps taken to assess the energy yield based on the main crop production, for both towns. In the course of these steps there are a number of estimates of the proportion of the total energy needs of the popula- tion that the major crops can provide.

Although the results are based on rather crude figures and should be treated with caution, the findings are remarkable. If the maize-producing households consumed all the maize they produced, their own urban maize production would contribute over 80% of their households’ energy requirements. This applies to both towns. Some of the self-produced maize was given away or sold but on average 82% and 74% was self-consumed in Morogoro and Mbeya, respectively. Taking this into consideration, self-produced maize still contributed over 60% to households’ energy requirements. The same calculation was made for the second important staple crop in each town, namely rice in Morogoro and beans in Mbeya. The 48 rice-producing households in Morogoro produced more than their total energy requirements. If sales are included, the contribution of their own production to their energy requirements is still very high at over 80%. In Mbeya, beans contributed only 6% of the energy requirements of the bean-producing households.

It is also possible to roughly estimate the contribution of these staple crops to the energy requirements of the whole study population and, therefore, of the whole population in the two towns (see Tables 6.2a and 6.2b, row 12). Assuming that the produce being given away or sold remains in town, the total produce has to be used for this estimate at town level, and not only the part that has been consumed by the household that produced it. The tables show that urban- produced maize and rice in Morogoro constituted more than three-quarters of the energy requirements of the town’s population, while in Mbeya, maize and beans contributed about 50%.

Table 6.2a Contribution of urban crop production to energy requirements: Morogoro (maize and rice)

1 2 3 4 5

no. of kg harvested aggregate kg kcal/kg aggregate kcal h'holds (average) (col. 1*col. 2) (from Platt 1962) (col. 3*col. 4) remarks

1 maize 215 997 214355 3630 778108650

2 rice 48 1430 68640 3520 241612800

3 total energy produced from maize and rice 1019721450

4 daily energy per capita 2200

5 annual energy requirements per capita (row 4*365) 803000

6 annual energy requirements per h'hold (row 5*5.4) 4336200 5.4 = av. h'hold size (Ch.3) 7 annual energy requirements of 215 maize-cultivating h'holds (row 6*215) 932283000

8 annual energy requirements of 48 rice-producing h'holds (row 6*48) 208137600 9 annual energy requirements of 300 households (row6*300) 1300860000

%

10 % contribution of urban maize production to energy req., 215 maize-producing h'holds (row 1/row 7*100%) 83.5 if 100% self-consumed % contribution of urban maize production to energy req., 215 maize-producing h'holds (0.82*row 1/row 7*100%) 68.4 82% self-consumed 11 % contribution of urban rice production to energy req., 48 rice-producing h'holds (row 2/row 8*100%) 116.1 if 100% self-consumed

% contribution of urban rice production to energy req., 48 rice-producing h'holds (0.72*row 2/row 8*100%) 83.6 72% self-consumed 12 % contribution of urban maize & rice production to energy req., 300 h'holds (row 3/row 9*100%) 78.4

Average percentages self-consumed were calculated as follows: all of it: 100% less than half of it: 30% most of it: 75% only a small part: 10% about half of it: 50% none: 0%

Table 6.2b Contribution of urban crop production to energy requirements: Mbeya (maize and beans)

1 2 3 4 5

no. of kg harvested aggregate kg kcal/kg aggregate kcal h'holds (average) (col. 1*col. 2) (from Platt 1962) (col. 3*col. 4) remarks 1 maize 172 1144 196768 3630 714267840

2 beans 89 113 10057 3390 34093230

3 total energy produced from maize and beans 748361070

4 daily energy per capita 2200

5 annual energy requirements per capita (row 4*365) 803000

6 annual energy requirements per h'hold (row 5*6.1) 4898300 6.1 = av. h'hold size (Ch.3) 7 annual energy requirements of 172 maize-cultivating h'holds (row 6*172) 842507600

8 annual energy requirements of 89 bean-producing h'holds (row 6*89) 435948700 9 annual energy requirements of 308 households (row 6*308) 1508676400

%

10 % contribution of urban maize production to energy req., 172 maize-producing h'holds (row1/row7*100%) 84.8 if 100% self-consumed % contribution of urban maize production to energy req., 172 maize-producing h'holds (0.74*row 1/row 7*100%) 62.7 74% self-consumed 11 % contribution of urban bean production to energy req., 89 bean-producing h'holds (row 2/row 8*100%) 7.8 if 100% self-consumed

% contribution of urban bean production to energy req., 89 bean-producing h'holds (0.83*row 2/row 8*100%) 6.5 83% self-consumed 12 % contribution of urban maize & bean production to energy req., 308 h'holds (row3/row9*100%) 49.6

Average percentages self-consumed were calculated as follows: all of it: 100% less than half of it: 30% most of it: 75% only a small part: 10% about half of it: 50% none: 0%

Regarding income generation it is clear that quite a number of the crop culti- vators sold part (and some even all) of their produce, thus earning an income from it. As for the most important crop, maize, almost a third of the maize- growing households sold part of their crop, but usually not more than half of their total production. Other crops were sold as well but usually by a (small) minority of crop cultivators. Income generation from crops is naturally seasonal. During harvesting months, many cultivators are forced to sell part of their harvest, so prices tend to be low. The crops of those with storage facilities, however, can fetch a better price when demand is higher. As one respondent in Morogoro ex- plained: “When crops are scarce, prices for crops go up and when the farmers sell their crops they get a lot of money.”

The money earned from selling crops was used for household expenditures like food, clothing, health costs and children’s education, as well as for preparing the farm for the next agricultural season. However, many more respondents in Mbeya than in Morogoro mentioned only the buying of food. From our data there appeared to be no relationship between the way the money was spent, on the one hand, and the person in the household who kept the money from the crop sales (the husband, the wife or both), on the other. Yet, it was conspicuous that in Mbeya it was mostly the wife who kept the money from crop sales, while in Morogoro it was either the husband or the husband and wife jointly. According to one respondent in Morogoro, however, this can make a difference: “Money obtained by selling crops is kept by either mother or father, but women keep the money properly without misusing it as compared to men.”