Cropping decisions are tough in a year of drought

Every year, producers make decisions about what crops to grow on which fields, whether to fallow some land, how much fertilizer to add, and how best to control weeds and pests. In a dry spring, the issues are similar, but the risks greater.

Drought conditions in 2001 and the winter of 2002 have resulted in some special considerations for this spring. On the positive side, the drought may have resulted in unused nutrients from last year being carried over in the soil. This could mean lower fertilizer requirements in 2002 on some fields. However, one should consider past nutrient management and use tools such as soil testing to help determine how much fertilizer to add. Newer technologies, such as liquid coulter banders, allow producers to delay fertilizer application until after the crop has emerged. This can also help reduce risk by extending the decision time to apply extra fertilizer if sufficient precipitation occurs.

Other consequences of last year's drought could make cropping decisions more difficult this spring.

Conditions have caused soil moisture levels to be much below normal, and less variable in local areas. In a normal year, spring soil moisture can vary greatly, not only due to variable precipitation, but also as a result of other factors such as differing heights of crop stubble for snow trap and the amount of moisture stored during the previous fallow period. Consequently, there is less reason to target crop types to certain fields based on existing soil moisture and the crop's moisture requirements. A producer considering fallow may find it more difficult to decide which field(s) to fallow if they all contain little soil moisture.

The dry soil conditions coupled with the low amounts of stubble and straw produced by last year's crop has also left many fields susceptible to wind erosion. Minimum tillage practices, such as low-disturbance direct seeding and using herbicides instead of tillage to control weeds, help to conserve the moisture and crop residue that is present.

While minimum tillage practices have increased dramatically over the past 10 years, surveys conducted by Agriculture and Agri-Food Canada suggest that over half of the annual cropland in Saskatchewan is not managed this way. Due to the low moisture and crop residue levels, there is still a possibility of crop failure or erosion with minimum tillage practices. However, minimum tillage will reduce the risk and severity.

In years of moderate drought, producers have often placed seed a little deeper than normal (e.g. two to three inches below the soil surface) where there is still enough soil moisture to get the crop started. This year, some may be faced with the prospect of placing seed in dry soil, regardless of the depth. This means many crops may not germinate or establish until they receive a significant rainfall. A producer may consider delaying seeding operations several weeks, hoping for rain. One could also spread the seeding operations over a wider time period to reduce the risk associated with spotty and infrequent showers. If dry conditions continue, producers should consider less-risky, more drought-tolerant crops, such as wheat, durum and barley.

There are other factors that make the decision of whether to fallow more complicated in a year following drought. Low crop residue levels from 2001 mean fields fallowed in 2002 will become erodible much sooner. On the other hand, some may choose to fallow due to the lower chances of successful stubble cropping, and the increased risk of grasshopper damage in 2002. If producers decide to fallow, there are ways to minimize erosion, such as using herbicides instead of tillage to control weeds. If rainfall is received part way through the fallow year, then erosion protection can be enhanced by seeding cover crops, green manure crops, or barrier strips.