A recent New York Times article by Julie Turkewitz addressed the record-breaking drought that keeps plodding through its second year, punishing much of South America, especially the Amazon rainforest. This rampant moisture starvation provides alarming glimpses into a future increasingly impacted by climate. She writes that in Brazil, wildfires fueled by searing heat and prolonged dry conditions continue consuming vast swaths of forests, wetlands and pastures, with smoke blanketing 80% of that huge nation. This leads to school closings and hospitalizations as black soot keeps penetrating residences.
Once described as our planet’s lungs, the Amazon Basin is becoming more a patient than a healer. Intensive farming in the tropics, heightened by the absence of winter, means cropland seldom enjoys the respites experienced by soils in temperate latitudes like ours. Tropical crop culture – with very little perennial vegetation – keeps eroding organic matter, and with it soil’s ability to sequester carbon and store moisture for non-rainy days.
Let’s leave this tropical soil mismanagement and flash back a couple years ago, targeting a periodical called Organic Life, in which Charles Eisenstein wrote an article titled “The Heartland.” With such a title, Kansas served as a logical starting point. He discussed sustainable farming in the Sunflower State, writing that the results of regenerative agriculture including intensive rotational grazing and no-till cropping are almost miraculous. He said that soil builds up quickly, commonly absorbing five to 10 tons of carbon/acre/year. Water infiltration also increases dramatically.
He gave an example of one old farmstead in Kansas where, after a few years of holistic grazing, the soil achieved an infiltration rate of 15 seconds for the first inch of water and 45 seconds for the second inch of rainfall.
Eisenstein pointed out that at the start of this experiment at the old farm mentioned, the rate of water infiltration was 45 minutes/inch. When water infiltrates this poorly most of it runs off during thunderstorms, carrying topsoil with it. Such runaway precipitation never reaches the dwindling aquifers needing recharging – in this case, the Ogallala Aquifer extending from north Texas to South Dakota. Quickly, springs, streams and wells go dry. Resulting parched soils provide no water for evapotranspiration, worsening droughts and dehydrating landscape, resulting in a flood/drought seesaw cycle instead of reliable year-round rain.
Desertification is commonly defined as land degradation in arid, semi-arid and dry sub-humid areas, known as drylands, resulting from many factors, including human activities and climatic variations. Eisenstein mentally led his readers southwest, to a friend’s ranch in a desertifying region of New Mexico. That friend had been photographed standing in grass up to his head – a species of grass that normally grows three feet tall. A previously dry stream on this rancher’s property now flows year-round, even in drought years. One mile past his property, the stream runs dry again, past the spread of another cattleman, who said his upstream neighbor was just lucky to get more, very localized rain.
Eisenstein mentioned that there are other stories in which dead springs come back to life, streams resume flowing and plant and animal species not seen in the area for decades reappeared.
Also in New Mexico, near the Texas panhandle, is Allan Savory’s Center for Holistic Management (CHM). Savory showed how much of the land near CHM became even more desolate than before. This land, once thriving with cow/calf operations – and during earlier times with buffalo and antelope – suffers from under-grazing, not over-grazing. He stressed that the critical linkage, from soils to crops to animals, had weakened, approaching the breaking point. The whole ecosystem had suffered, including those at the top of the food chain – humans.
During the 1960s, Savory, originally a citizen of Rhodesia, worked as a research biologist and game ranger. Savory studied interrelated problems of poverty, wildlife and grassland resources that were gradually desertifying. His land management ideas eventually alienated local political powers, resulting in exile and emigration to the U.S. In Savory’s part of New Mexico, cow/calf grazing operations were and continue to be increasingly uncommon, as steers are moved off grass and onto paved confinement feedlots at much younger ages. Savory stressed that fragile land suffered from reduced animal numbers and needed to be grazed. Manure from grazing animals provides organic matter and other soil nutrient benefits that sustain grassy-type, mostly perennial crops, maintain soil’s water retention capacity, enhancing biodiversity.
At CHM, Savory conducted experiments, successfully demonstrating that classic cattle grazing practices can reverse sad trends in which soil, crops, livestock and people suffer. He’s shown that fencing cattle in an area greatly improves sward health, compared to un-pastured land on the other side of the fence. The grazed paddock and the adjacent un-grazed parcel received the same meager 10 – 12 inches of rain, proving that grazed portions better utilize their limited precipitation. Savory wrote that large quantities of urine and feces voided by huge grazing herds catalyzed the microbial activity necessary for healthy soil.
How does losing soil carbon intensify climate change? The increasingly common soybean/corn “non-rotation,” with its non-fibrous root systems, does not build soil. In this scenario, fibrous-rooted small grain cover crops are conspicuously absent; their presence would help retain nutrients, soil and snow during winter. Soil’s OM is approximately 58% carbon by weight and a six-inch deep acre of topsoil is presumed to weigh 1,000 tons (2 million lbs.). So for each percent of OM lost on an acre, 11,600 lbs. of carbon are liberated into the atmosphere as carbon dioxide. Losing that 1% OM also reduces the water-holding capacity of that soil by about 1.5 quarts/square foot.
Increasingly, climate change developments forge weather patterns that are in the flood/drought seesaw category instead of reliable year-round rainfall patterns. Weather extremes like hurricanes and drought-based shrunken river transportation arteries are increasingly blighting our planet.
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