4 MILPA/FRUIT TREE INTERCROPPING SYSTEM IN SUSTAINABLE HILLSIDE MANAGEMENT PROJECT

578



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Cortés et al.



Figure 23.3 Living wall terrace technology in the semihumid tropics of Mexico, developed by the Instituto

Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. (Photos courtesy of Antonio Turrent F.)



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579



slopes in semihumid regions where the living wall terrace

technology was developed.

The MIFT system consists of maize and beans cultivated

either in association with one another or in a relay cropping

pattern, intercropped between rows of peach trees in temperate regions, and between rows of industrial trees, such as

coffee in semitropical areas. Peach trees are trained in the

Tatura trellis system, and coffee trees in the central leader

system. Both species are fertilized with N, P, and K every

year. Fruit and coffee trees cannot be planted very close to

each other in rows as is the case for Glyricidia sepium. Spacing in rows is between 0.75 m and 1.0 m, with 9 m between

rows in contour. Peach and coffee trees are planted in the

middle of the rows, which have a width of 3.0 m. The free

strip of 6.0 m in width between two rows of trees is occupied

by maize and beans in eight rows of 0.75-m width (see

Figure 23.4).

Thus, trees occupy one-third, and maize and beans twothirds, of plot land surface. Maize is fertilized with N, P, and

poultry waste, and beans with N and P only.

Relay cropping patterns consist of beans, which are

planted in February, and maize, which is planted 1 month

later between two rows of beans. Land preparation and cultural practices are done by hand. Peaches bloom from January

to February and are picked from late May to early June. Beans

are harvested in June just after the rainy season begins. Then

maize is grown by itself and harvested in October. Subsequently, corn stalks are cut and used to form the runoff filter

discussed previously. This system is pictured in Figure 23.5.

In association cropping pattern, land preparation is completed using animal traction or manual labor. If land preparation is done in late fall, maize and beans can be planted in

mid-April. Residual soil moisture from rainfall of the previous

year allows seed germination and plant growth before the

onset of the May rainy season. Harvest time is in October.

However, if land is not prepared on time, planting is delayed

until the rainy season begins, and the crops are harvested in

December. When the rainy season is delayed, as in 2003, crops

fail because of drought stress, and farmers have to replant



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Cortés et al.



Figure 23.4 The milpa system intercropped with peach and coffee trees on hillside plots in the Mazateca

and Mixe regions, Oaxaca, Mexico. (Photos courtesy of José I. Cortés F. and Mariano Morales G.)



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Figure 23.5 The milpa system intercropped with fruit trees illustrating the runoff filter as a key control of soil erosion on hillsides.

(Photos courtesy of José I. Cortés F.)



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Cortés et al.



the crops, using shorter-season local maize cultivars. Under

these conditions, however, the growing season for peaches is

not altered. The MIFT system, described in this chapter, is

being compared with a system of maize cultivated as a

monocrop and managed under traditional (control), improved,

and no-tillage systems.

23.5 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-andburn 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



© 2005 by Taylor & Francis Group, LLC



Year

2000

Treatment

MMSB1

MM3

MMI4

MMNT5

MIFT-P1.06

MIFT-P1.0(p)7

MIFT-P0.758

MIFT-P0.75(p)9

LSD0.0510



2001



2002



Maize Maize Maize Peach

1.10

2.49

1.85

2.70

3.43

4.96

3.37

3.06



1



0.40

4.32

2.69

4.68

4.38

7.90

6.00

8.71



0.40

1.81

2.71

4.79

4.90

7.00

3.71

4.86



N/A2

N/A

N/A

N/A

2.6

2.6

3.7

3.7



Average



Accumulated

Yield



Yield Maize



Maize Peach



0.63

2.87

2.38

4.06

4.29

6.62

4.36

5.54

0.58



1.9

8.63

7.25

12.18

12.72

19.86

13.07

16.62



N/A

N/A

N/A

N/A

2.6

2.6

3.7

3.7



Accumulated

Cost

(US $)



Accumulated

Gross Income

(US $)



B/C

Ratio



1791

4137

3273

3344

4951

5746

5763

6554



420

1898

1580

2679

4098

5668

4727

5507



0.23

0.46

0.48

0.80

0.83

0.99

0.82

0.84



Maize in monocrop under slash and burn system.

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.



Hillside Agriculture and Food Security in Mexico



Table 23.1 Yields (Mt ha−1) of Maize and Peaches, and Economic Parameters with Two Cropping Systems

Under Several Treatments in Mazateca Region



2



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Cortés et al.



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



© 2005 by Taylor & Francis Group, LLC



Hillside Agriculture and Food Security in Mexico



585



$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



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Cortés et al.



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).



© 2005 by Taylor & Francis Group, LLC



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23.6 CONCLUSIONS

Results from the SHMP indicate that it is possible to achieve

food security and maintain and/or improve soil quality in

smallholder hillside agriculture systems. However, there are

many challenges to overcome in the coming years. Small farmers and researchers and development experts who are working on these problems tend to agree about what needs to be

done. They are all interested in finding solutions. More people

from several indigenous rural communities are applying to

participate in the project. And community, municipal, state,

and federal institutions are willing to support small-farmer

initiatives and to support the field research activities that are

required to improve and diversify the MIFT system in several

ecosystems. The future of food security for small farmers

undertaking hillside agriculture in Mexico depends in part on

the degree of cooperation generated between small farmers

and national institutions in the coming years.

REFERENCES

Cortés, J.I., A. Turrent, E. Hernández, R. Mendoza, L.A. Lerma, E.

Aceves, H. Mejía, G. Narváez, P. Díaz, and A. Ramos. 2001.

Proyecto Manejo Sostenibles de Laderas. Subproyecto III: Tecnologías Alternativas Sostenibles. Informe de Actividades. Colegio de Postgraduados, Montecillo, Mexico.

Cortés, J.I., A. Turrent, P. Díaz, E. Hernández, H. Mejía, R. Mendoza, A. Ramos, and E. Aceves. 2003. Proyecto Manejo Sostenibles de Laderas. Subproyecto III: Tecnologías Alternativas

Sostenibles. Informe de Actividades. Colegio de Postgraduados,

Montecillo, Mexico.

Etchevers, J.D., C. Hidalgo, J. Padilla, R.M. López, C. Monreal, C.

Izaurralde, B. Rapidel, F. deLeón, M. Acosta, and M.A. Vergara.

2003. Proyecto Manejo Sostenible de Laderas. Subproyecto II:

Metodología de la Medición de la Captura de Carbono. Informe

de Actividades. Colegio de Postgraduados. Mexico.



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Figueroa, B., M. Martínez, L. Aceves, et al. 2003. Proyecto Manejo

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