How does slash and burn farming affect the environment

How is slash and burn agriculture Practised? What is agriculture explain its main features? How is slash and burn agriculture Practised class 10th? Why is slash and burn used? What is the other name of slash and burn agriculture? What does slash and burn mean? What is slash and burn kids? Is slash and burn good or bad? Does slash and burn increase soil fertility? Did the Mayans use slash and burn?

Did the Aztecs use slash and burn? What do the Mayans Incas and Aztecs have in common? What did the Mayans do for a living? After it dries out, the area is set ablaze. In their wake they leave a destroyed ecosystem that was the former home to numerous species of plants, insects, and animals.

It can take up to twenty years for this land to recover and be useful again. Hidden Danger 1: Soil Quality is Depleted to Dangerous Levels Initially, soil quality gets a boost from the new addition of ash and other biomass in the aftermath of slash and burn activity.

After a few years however, those nutrients are used up and farmers must leave the depleted soil in search of other land. After the plots are abandoned, it can take up to twenty years for the soil to reach its optimum health again.

Healthy soil is a result of a relationship between the native trees, insects, and moisture in the area. No wonder there is an ongoing search for alternatives to burning in traditional farming. Principally, there are two approaches to fire-free fallow cleaning: slash-and-mulch, which provides a long-term nutrient release, and slash-and-incorporate, which stands for a quicker mineralization Szott et al.

Thanks to its efficiency, its low cost and easy management, slash-and-burn farming is still popular with Maya peasants. Less soil harming, fire-free managements would only be accepted if they provided similar benefits as slash-and-burn farming or offered additional advantages, such as increased soil fertility in the long term. Therefore, the aim of the present study was to compare a slash-and-incorporate management with classical slash-and-burn farming regarding their effects on main physiochemical soil properties in a milpa polycropping system.

Furthermore, the yield provided by each management was also evaluated. The annual precipitation is mm and the mean temperature Its texture is sandy loam and its original pH was 7. The trial was installed on a five years lasting natural fallow in an area surrounded by secondary tropical dry forest.

There were two treatments with four replications each. Consequently, the trial field was divided into eight plots m 2 each. The first treatment consisted in slash-and-burn farming. Therefore, one part of the field was slash-and burned in April , following the traditional milpa management in the region.

In the second treatment, the management was identical except for a lack of burning: After slashing, the dried biomass was chopped and incorporated to the soil surface at a depth of cm using a tiller table 2. Table 2 Crop management activities during the implementation of the trial in A dibble stick was employed to make holes at regular intervals, into which the seeds were dropped without other working of the ground Cowgill, There were no further nutrition and disease control measures.

All plots were rainfed. Weeds were removed manually and pests were monitored with a yellow sticky trap which did not indicate the need of control. Soil sampling took place bimonthly from February to December A grid sampling consisting of four columns at 8 m equidistance and eight rows was applied. This resulted in four sampling spots per plot. Using an auger, samples of g were taken at 15 cm depth for measuring soil organic matter and 60 cm depth nutrients, pH, cation exchange capacity, salinity, bulk density.

Bulk density was determined from a core sample. Harvesting was done weekly for twelve weeks. Statistical analysis. Normality of distribution of means was tested using the Shapiro-Wilk test. After one cropping cycle, mineral N was highest in the fire-free treatment table 3. The burned treatment showed a notable increase of N after burning followed by a slight decrease simultaneously to the vegetative growth of the crops, which intensified with the beginning of the raining season figure 1.

As for P, the burned treatment showed a slight increase after burning, which was reversed after seeding; the unburned treatment was continuously below the burned one figure 2. It was observed that the intense precipitation during the raining season decreased the soil reserves of N and K in the burned treatment but not in the unburned one. This can be attributed to a higher nutrient leaching in slash-and-burn agriculture Szott et al.

However, after one production cycle, soil reserves of N and P remained considerably low in both treatments. Consequently, for subsequent production cycles, these nutrients have to be provided by additional organic or mineral sources Kato et al. As for soil reserves of K, they increased through both treatments, but stronger through burning figure 3 : Exchangeable K rose drastically after burning and started to decrease after the first intense rainfalls; the fire-free management ended up almost kg ha -1 below the burned variant.

Regarding Ca and Mg, the alternative treatment decreased their reserves, while burning caused an increase table 3. Yet, these nutrients are relatively abundant in the soils of the region. In this regard, nutrient availability might play a more important role than nutrient supply. A slightly alkali pH of 7. This is a higher pH by trend compared to the fire-free management, which showed a pH of 7.

The burning also raised the salinity. Finally, burning increased the bulk density more severely than the alternative treatment table 3. In contrast, squash yield was higher with slashing-and-burning table 4. Figure 1 Development of soil-reserves of mineral N ammonium and nitrate during a milpa cycle, comparing slash-and-burn-farming and a fire-free management, in kg ha Figure 2 Development of soil-reserves of plant-available P during a milpa cycle, comparing slash-and-burn farming and a fire-free management, in kg ha Figure 3 Development of soil-reserves of K during a milpa cycle, comparing slash-and-burn farming and a fire-free management, in kg ha Milpa has sustained the nutrition of Mesoamerican societies for centuries; and it still has the potential to provide food security and sovereignty for Maya peasants.

Even more: thanks to its agrobiodiversity, milpa is highly resilient and adaptive to changing environmental conditions, which makes it a source of inspiration for confronting climate change.

Thus, there is a need for milpa in the 21 st century. Milpa has been widely related with slash-and-burn farming, which today is considered an unsustainable practice that decreases soil fertility in the long term. The resulting layer of ash provides the newly-cleared land with a nutrient-rich layer to help fertilize crops. However, under this method, land is only fertile for a couple of years before the nutrients are used up. Farmers must abandon the land, now degraded, and move to a new plot—clearing more forest in order to do so.

Slash-and-burn agriculture has been used in Central America and Mexico for thousands of years.