18. The most commonly cited benefits of a switch to animal drawn plows are: an expansion in area cultivated; high yields; reduced labor requirements; and development of animal husbandry skills. In this section, we will examine the existing empirical evidence on the different effects of the transition to the plow. Our review of the literature identified 22 survey studies that tried to evaluate these effects. All of these studies were contemporaneous comparisons of holdings with and without animal traction in the same agro-climatic environment. We are not aware of any comparisons over time of households that switched from handhoes to animal draft power. Summary results from these studies are presented in Table 3.
Table 3. Summary of the evidence on the effects of animal traction.
|
|
Cases Measured (Out of 22) |
Number of Cases With Effect |
|||
|
Positive |
NSD |
Negative |
Area Effect |
||
|
Area Per Farm |
|||||
|
All Cases |
17 |
17 |
|
|
With AT 6.6 ha |
|
Cases in Favorable Zones |
9 |
9 |
|
|
With AT 6.8 ha W/O AT 3.5 ha |
|
Cases in Unfavorable Zones |
8 |
8 |
|
|
With AT 6.3 ha W/O AT 3.0 ha |
|
Area Per Person |
|||||
|
All Cases |
19 |
19 |
|
|
|
|
Cases in favorable Zones |
11 |
11 |
|
|
With AT 0.68 ha |
|
Cases in unfavorable Zones |
8 |
8 |
|
|
With AT 0.58 ha |
|
Land Use for Market Crops |
|||||
|
All Cases |
19 |
12 |
7 |
- |
|
|
Cases in Favorable Zones |
11 |
8 |
3 |
- |
|
|
Cases in Unfavorable Zones |
8 |
4 |
4 |
- |
|
|
Yield Per Hectare |
|||||
|
All Cases |
14 |
4 |
8 |
2 |
|
|
Cases in Favorable Zones |
10 |
4 |
6 |
- |
|
|
Cases in Unfavorable Zones |
4 |
- |
2 |
2 |
|
Unfavorable areas have less than 750 mm of rain per annum and practice upland farming.
NSD: No significant difference.
Source: Pingali et al (1987).
(i) Area effects
19. Studies that compare handhoe and animal traction farms generally find the latter to be larger in size than the former. Of the 17 studies reporting on area effects, all found a positive area effect. In general, animal traction farms were found to be twice as large as handhoe farms (see Table 3). The area effect was the same for cases in the favorable areas (above 750 mm of rain per annum) and for cases in the unfavorable areas (below 750 mm of rain per annum). These findings suggest that the transition to the plow is associated with an expansion in the private area cultivated, and therefore, an increase in agricultural production on the animal traction farm. Whether there is also an aggregate area expansion depends on the extent of land pressure in the area. Where there is substantial fallow land, aggregate cultivated area increases; on the other hand, where there is no fallow land, expansion in cultivated area can only come from a displacement of tenant farmers, and in this case, there is no aggregate area expansion.
(ii) Cropping pattern effects
20. A related question is what crops are grown on the additional area. Of the 17 cases that reported an expansion in area, 12 reported that the additional area was used for cash crop cultivation (cotton, groundnuts, rice, maize etc). The expansion in area under cash crops is more likely to occur in favorable than in unfavorable zones.
(iii) Yield effects
21. Experimental station studies have consistently shown a positive yield effect due to tillage. Yet objective comparisons of handhoe farms with animal draft farms have generally failed to show any significant yield effects. As shown in Table 3, 14 of the 22 cases examined presented yield effects of plowing; of these, 8 reported no significant difference in yield between plowed fields and fields tilled with handhoes. Even for the remaining studies, when proper accounting was made of other effects such as fertiliser use, extent of fallow land that was brought under cultivation, etc., there was no significant difference between the yield of handhoe and animal draft farmers.
22. How do we explain this apparent anomaly between experiment station results and the contemporaneous comparisons between users and nonusers of animal draft power? Let us start by noting that - apart from subsoiling - it is almost always technically feasible to achieve a given quality of tillage by using a plow or manual techniques. So, when yields between the two techniques remain the same, we can only conclude that farmers switching to the plow were not motivated by improvements in tillage quality, but that they were more interested in the area expansion or labor saving benefits accruing through the transition. Interestingly enough, comparisons of animal draft and tractor farms also showed no significant difference in yields. We are not saying that yield improvements are not possible; it is just that the farmers who made the transition were not motivated to do so in order to achieve these improvements. Most experimental studies compared plowed plots with unplowed control plots, i.e., plots that were directly seeded with no land preparation of any sort. They were not comparing plots tilled by hand versus plots tilled by animal drawn plows. Where hand tillage was indeed being used in the control plot, there were substantial differences in the quality of tillage between the two plots. Hence, the significant positive results. We are not aware of any studies where an attempt was made to hold tillage quality the same between the two groups - i.e hand-tilled and plowed plots.
(iv) Effects on labor use and labor productivity.
23. There is general agreement that a transition from the handhoe to the plow reduces the labor requirements during the land preparation period. (Assuming, of course, that we are at the grass-fallow stage or beyond, as we discussed earlier on; otherwise, the switch to the plow in shifiting cultivation systems is not labor saving). Animal traction farmers do face higher weeding and/or harvesting labor requirements due the larger area cultivated, but most studies agree that labor requirements per hectare decline relative to handhoe farms. Consequently, labor productivity (output/manhour) increases significantly on animal traction farms relative to handhoe farms.
(v) Income effects
24. Does the adoption of animal draft power lead to higher net incomes than for handhoe farms? The income effect is a combination of the area effect, the cropping pattern effect, the yield effect and the labor effect. Of the 22 contemporaneous comparisons 16 indicated significantly larger income per household on animal traction farms. The income of animal traction households was found to have been two to five times that of handhoe using households.
