Results

Results obtained on two hillsides with a 35% slope in the Mazateca region during the first 3 years, indicate that the average yield of maize varies widely between treatments. It ranged from 0.63 to 6.62 Mt ha-1, as reported in Table 23.1. Yields for the traditional slash-and-burn system were ten times lower than those for milpas intercropped between rows of peach trees with a spacing of 1.0 m in the rows, and using poultry waste manure for the maize along with mineral fertilizers. Yields for other treatments of monocropped maize were also improved greatly, especially under no-tillage conditions. The main difference in yields between monocrop maize treatments is due to mineral and organic fertilization. In slash-and-burn systems, maize is not fertilized, while in the other three treatments, N rates range from 80 to 120 kg ha-1 and P from 35.2 to 44 kg ha-1. In the case of no-tillage treatment, poultry waste is applied at a rate of 2.0 Mt ha-1 every year in addition to the application of N and P. Then it can be concluded that the higher yields associated with this treatment are primarily due to supplemental organic fertilizers.

Yields of maize under MIFT system treatments confirm the response to poultry waste, applied at an equivalent rate of 2.0 Mt ha-1. Yield response was 1.0 Mt ha-1 higher for maize intercropped between rows of peach trees with a spacing of 1.0 m than for maize intercropped between rows with a spacing of 0.75 m. Reasons for this variation are currently being analyzed.

Maize yield responses for field trials conducted for the project indicate that it is possible to produce sufficient quantities of this staple crop to sustain small farm families simply by improving the monocrop system. However, improvements

Table 23.1 Yields (Mt ha-1) of Maize and Peaches, and Economic Parameters with Two Cropping Systems Under Several Treatments in Mazateca Region

Year

Accumulated

Table 23.1 Yields (Mt ha-1) of Maize and Peaches, and Economic Parameters with Two Cropping Systems Under Several Treatments in Mazateca Region

2000

2001

2002

Average

Yield

Accumulated

Accumulated

Cost

Gross Income

B/C

Treatment

Maize

Maize

Maize

Peach

Yield Maize

Maize

Peach

(US $)

(US $)

Ratio

MMSB1

1.10

0.40

0.40

N/A2

0.63

1.9

N/A

1791

420

0.23

MM3

2.49

4.32

1.81

N/A

2.87

8.63

N/A

4137

1898

0.46

MMI4

1.85

2.69

2.71

N/A

2.38

7.25

N/A

3273

1580

0.48

MMNT5

2.70

4.68

4.79

N/A

4.06

12.18

N/A

3344

2679

0.80

MIFT-P1.06

3.43

4.38

4.90

2.6

4.29

12.72

2.6

4951

4098

0.83

MIFT-P1.0(p)7

4.96

7.90

7.00

2.6

6.62

19.86

2.6

5746

5668

0.99

MIFT-P0.758

3.37

6.00

3.71

3.7

4.36

13.07

3.7

5763

4727

0.82

MIFT-P0.75(p)9

3.06

8.71

4.86

3.7

5.54

16.62

3.7

6554

5507

0.84

LSDo.0510

0.58

1 Maize in monocrop under slash and burn system.

2 Non applicable.

3 Maize in monocrop under traditional management in roturated soil.

4 Maize in monocrop under improved management in roturated soil.

5 Maize in monocrop under no tillage system in the same site where soil is roturated.

6 Milpa intercropped between rows of peach trees with a spacing of 1.0 m in the row in roturated soil.

7 Same as 6 but maize receiving poultry waste in addition to mineral fertilization.

8 Milpa intercropped rows of peach trees with a spacing of 0.75 m in the row in roturated soil.

9 Same as 8 but maize receiving poultry waste in addition to mineral fertilization.

10 Least significant difference for last seven treatments in the same plot only.

Source: Adapted from Cortés F., et al. 2003. Proyecto Manejo Sostenibles de Laderas. Subproyecto III: Tecnologías Alternativas Sostenibles. Informe de actividades. Colegio de Postgraduados, Mexico City.

On po Cu in maize production alone for small farmers with 2- to 3.5-ha plots will not greatly improve their socioeconomic situation. In the next section, we analyze economic parameters of several treatments discussed above.

Accumulated cost data in Table 23.1 indicated that monocropping with rotated soils and in a no-tillage system was 1.8 to 2.3 times more expensive than monocropping in a slash-and-burn system, and the MIFT system was 2.8 to 3.7 times more expensive. Accumulated gross income for the alternative systems, however, showed a reverse situation. Incomes were 3.8 to 6.4 times higher for the alternate monocropping in no-tillage systems, and 9.7 to 13.5 times higher in the MIFT system. These differences are reflected in the benefit-cost (B/C) ratio, which varied widely between treatments. Monocropped maize for the slash-and-burn system had the lowest B/C ratio, equal to 0.23. This value was twice as high for monocropped maize under crop rotation, and 3.7 to 4.3 times higher for monocropped maize in a no-tillage system and for maize grown in the MIFT system.

These results are consistent with reports of socioeconomic evaluation studies carried out by staff members of the SHMP, which indicate that small farmers, cropping maize alone under traditional systems are in a critical socioeconomic situation (León et al., 2001). Maize production in no-tillage systems appears to be a viable alternative since its B/C ratio was very close to the B/C ratio for the MIFT systems. Although future maize yields in no-tillage systems could be improved, maize prices are going to be a major limiting factor in obtaining a higher B/C ratio. Economic analyses were based on US $0.22 kg-1 for maize, which is average for the region.

For MIFT systems, it is expected that the B/C ratio will increase as peach tree yields increase in the coming years. The assumption used for this project is that yields will be 6 to 8 kg tree-1 during a productive life of 15 to 17 years. Consistent with recent field observations, yields averaged about 5 kg tree-1 in 2003. It is assumed that in 2004 and subsequent years that potential yields will be actualized. Economic analyses used an average price of US $0.50 kg-1 for peaches. During late spring, however, consumers pay from US

$1.00 to US $2.50 kg-1, depending on fruit quality. Target regions of the SHMP are able to produce quality peaches that can compete in the market.

Intercropped peach trees, with tree spacing of 0.75 m and 1.0 m in the row, resulted in LERs of 0.48 and 0.39, respectively. A yield hypothesis for the MIFT system was that intercropped peach trees, in one-third of the land parcel, would produce 50% of the yield of monocropped peach trees, which would mean a LER of 0.50. Thus, the LERs obtained thus far tend to support this yield hypothesis, and suggest also the capability of the MIFT system to increase land use efficiency in hillside agriculture.

Peach trees in the MIFT system are more vigorous than those in the monocrop system. This difference is observed early in the growing season, when peach trees are growing alone, since annual crops are not still planted or are growing slowly. This is also the dry season. Thus, it is reasonable to assume that peach trees in the MIFT system are growing without any competition for soil water, and under better soil moisture and nutrition conditions, because of the runoff filter along the row of trees that increases water infiltration and diminishes soil erosion.

Research on carbon sequestration and soil erosion, which is also being undertaken by researchers involved with the SHMP, indicates that the MIFT system improves also soil quality (Etchevers et al., 2003; Figueroa et al., 2003).

Results in the other two SHMP regions follow similar trends. However, local maize varieties are susceptible to diseases at the end of the growing season in areas where maize is intercropped between rows of coffee trees, thus affecting yields. Conventional breeding research is resolving this problem, as well as height and lodging problems observed in the three regions.

In addition to peaches, other deciduous fruit trees can be included in the MIFT system in temperate zones. Thus, apples are also being introduced into the MIFT system in order to advance its diversification as soon as possible. Fruit tree diversification rates will depend on the availability of fruit cultivars adapted to the study regions, and their ability to become cash crops for small farmers.

In semitropical areas, it will be important to identify fruit tree species that can be trained under the Tatura trellis system to form a living wall. Research on this topic has been initiated in the states of Veracruz and Chiapas through a joint project between the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias and the Colegio de Postgraduados.

The no-tillage system adapted to the highland conditions of small farmers in the Cuicateca, Mazateca, and Mixe regions is also needed for improvement and diversification of the MIFT system for steeper hillsides and shallower soils. Some work has been done on identification of cover crops, and a field experiment on methods of land preparation, planting dates, and mulching has been initiated in the Cuicateca region, where soil erosion is more critical.

Access to inputs and/or services required to support technological innovations in these isolated areas is another topic that needs to be addressed. The SHMP is currently establishing family micronurseries in rural communities in order to propagate peach trees and other fruit species. It is also working on alternate methods to establish fruit trees in the field in order to diminish as much as possible initial investments related to the MIFT system. Planting stratified peach seeds in contour rows at recommended row spacing, in order to establish rootstocks, seems to be a viable alternative. They can later be grafted by farmers themselves.

Farmer training about the MIFT system and other technological innovations is another step in order to achieve SHMP objectives. Specialists in training and technology transfer have proposed a field school approach to train selected small farmers in their own communities. Today, there are several field schools functioning in the three SHMP target regions. Small farmers, after receiving training, teach their neighbors how to adopt the MIFT system (Jiménez et al., 2003).

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