Precious Soil is Dirty Work

Saving Soil

Soil conservation has been a priority amongst farmers in Alberta and the rest of the country for in the past two decades, thanks to some hard historical lessons. In the Prairies at the turn of the century, huge sectors of natural grassland were ploughed without regard for the stability of the soil or its capacity to grow crops. Inappropriate agricultural practices, population explosion, drought and an economic depression led to what was called the "Dirty ’30s,” or the Western Dust Bowl. Western agriculture eventually recovered with the help of technological progress in pesticides, fertilizers and new varieties of field crop seeds, but time-honoured practices like crop rotation were virtually abandoned. Monoculture, a practice that would inevitably lead to soil degradation, took place all across the country. History began to repeat itself; farmers saw an increase in soil erosion, among other problems.

During the 1980s, the agricultural sector began once again employing the techniques of polyculture: crop rotation, direct seeding, decreasing tillage of the soil, and using forage crops on marginal lands. Polyculture uses multiple crops in the same space, in imitation of the diversity of natural ecosystems. It includes crop rotation, multi-cropping, intercropping, companion planting, encouraging beneficial weeds, and alley cropping.

Crop rotation is the practice of growing a series of different types of crops in the same space, to replenish the soil. It improves crops’ resistance to disease, provides habitat for more species, and increases local biodiversity. It can also improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants.

Direct seeding is the practice of planting with little or no disturbance to the soil. Residue from the previous crop is left standing to trap moisture in the soil, and provide cover for young shoots. The benefits are obvious: less erosion, less fuel is consumed in planting, moisture and soil integrity are maintained, and the previous crop serves as protection and provides nutrients. In Alberta in 2001, approximately 63 per cent of all acres in the province were direct seeded, with the remaining 37 per cent by conventional systems. These statistics are almost the complete reversal from data from 1994, where 63 per cent were using conventional seeding systems.

Techniques Alberta farmers use today are improving the soil for future crops – and future Albertans.