Climate-smart agriculture is a sustainability solution

This guest blog post was contributed by Maria Gabriela Cruz of Elvas, Portugal.

The loud and angry debates over crop-protection products in Europe can give the false impression that farmers like me are prone to over-use chemicals on what we grow.

That’s ridiculous, especially as we strive each day to practice the conservation agriculture that protects our soil, water and air.

We certainly need good crop-protection products, and I was pleased when regulators from four countries in the European Union determined earlier this year that glyphosate deserves to remain an approved product for safe and successful weed control.

Yet there’s so much more to what we do on our farm in Portugal, where we grow corn in a hot and dry climate.

One of our biggest challenges involves rainfall. In every ten-year period, we can expect four or five years of drought. The last time we suffered from it was 2019, and Portuguese scientists are predicting increased periods of drought and heat and less frequent but more intense periods of rain.

Because water is such a scarce resource, especially during the summer, we use it with great care—and that means adopting irrigation technologies that maximize our efficiency.

We receive water for irrigation from a public dam. It is delivered to our crops in precise quantities and mostly during the night and early morning to maximize the efficiency of water and energy use.

To achieve this goal, we use probes to monitor the moisture in our farm’s soil. (See one in this video.) They report information in real time, which we consult routinely. We combine this data with six-day weather forecasts, including information about temperature, humidity, and wind. We track “evapotranspiration,” which is the loss of water from the soil and plants into the atmosphere. We also look at satellite photos, in search of emerging trends and threats.

All of this helps us make smart decisions about how we irrigate our crops, so that our investment in water feeds what we’re trying to grow rather than vanishes into the ground or air. Our irrigation equipment is observed every day and the system alerts us to blockages in our lines, which we fix immediately.

Every drop counts.

This careful and strategic approach enables our other sustainable practices, such as our use of fertilizers. Again, we look to the soil to see what it needs. Our goal is to provide an exact amount of fertilizer at precisely the right moment. We analyze the soil constantly, and always want to know at the end of a growing season if fields have maintained or improved their quality.

Occasionally we receive too much precipitation, in blasts of heavy rainfall that that can wash away our soil. These episodes, which usually come in the winter, are the main cause of poor soil fertility in Portugal. Our summers make the downpours even more damaging because the hot temperatures and dry periods deplete the soil of the organic matter than would help prevent erosion.

Our solution to this problem involves a sustainable response of cover crops and no-till agriculture.

On our farm we tend to have our soil always covered by a crop or biomass, such as the straw from the previous season. This offers a blanket of protection against the stresses of rain, wind, and heat.

Integrated Pest Management (IPM) strategies were implemented on our farm in 2003, providing information that allows us to evaluate the economic threshold of a pest. This information tells us when an insect’s population level or the extent of crop damage exceeds the cost of controlling the pest. That information is critical to our sustainability and supports our ability to apply crop protection products precisely and only when economically unavoidable.

We also practice no-till farming. By resisting the traditional method of controlling weeds by churning the soil, we keep moisture locked into the dirt. This may be our most efficient, economically, socially, and environmentally sustainable practice, helping us sequester carbon in the ground. This step helps us grow better crops and assists in the fight against climate change.

To make these integrated systems work, however, we need safe and effective herbicides such as glyphosate or a substitute herbicide that controls weeds at the time of sowing a crop. Without them, we’d have to control weeds with older and less sustainable practices that would lead to environmental damage and lower considerably the yield due to weeds alive and competing with our crop for sun, water and nutrition from the soil.

In time, technology may give us non-chemical alternatives to weed control—but we don’t have them now, and so our sustainable practices require the tools of crop protection.

They are essential to everything we do on my farm and growing the food that we all need.

Maria Gabriela Cruz manages a 500-hectare farm in Elvas, Portugal that has been in their family for over 100 years. Growing maize, wheat, barley and green peas, they use no-till or reduced till methods on the full farm.  She has grown biotech maize since 2006. Ms. Cruz is President of the Portuguese Association of Conservation Agriculture, a member of the Global Farmer Network and the 2010 Kleckner Award recipient.  www.globalfarmernetwork.org