Blue lupines in southern California
June 1, 2016 | David F. Coppedge

Peas and Prosperity

A healthy plant community relies on natural mechanisms that agricultural scientists can tap into.

When agricultural chemist George Washington Carver urged poor southern farmers to plant peanuts, they resisted. But Carver knew why it was in their best interest to rotate crops with legumes (members of the pea family): they fix nitrogen. Although nitrogen is abundant on earth, comprising 78% of the atmosphere, it cannot be used by plants unless its tough triple bonds are broken. Once dinitrogen atoms are separated, they can be combined into useful molecules like ammonia, and included in life’s proteins. The fixing of nitrogen is actually done by microbes that live in symbiotic relationships with the roots of legumes. The plants construct nodules to nurture the bacteria. Inside the bacteria, specialized enzymes called nitrogenases break the triple bonds at room temperature—a feat scientists have not yet been able to imitate. Fixing nitrogen commercially requires high temperatures and pressures. Lightning is another source that can fix atmospheric nitrogen.

Like Carver, agronomist Perry Miller of the University of Montana is encouraging farmers to plant legumes. Science Daily explains why crop rotation with legumes will bring “peas on earth” to farmers facing economic swings and high expenses for commercial fertilizers. “A cropping system that is more reliant on soil organic nitrogen fixed by legumes and less reliant on expensive bag fertilizer seems to economically stabilize [farm income] in a very important way,” Miller advises.

Blue lupines are legumes that fix nitrogen in the soil. Photo by David Coppedge.

Blue lupines are legumes that fix nitrogen in the soil. Photo by David Coppedge.

Miller is not alone. Over in Europe, an international team of scientists feels it’s “win-win situation for the environment and the economy when it comes to introducing legumes into agricultural systems,” PhysOrg reports. Only 2% of the arable land in Europe is used for legumes, which include clovers, lupins, lucerne and faba beans. Though not as attractive as crops for farmers wanting a quick return on investment, the benefits smooth out the highs and lows, showing good profit margins over the long term.  “Contrary to popular belief, these findings show that the benefits of diversifying cropping systems through the inclusion of legumes can be both environmental and economic,” the team reported in Frontiers in Plant Science. “Based on real case-study regions, the results demonstrate great potential for implementation.”

Natural fertilization is not limited to the roots. Scientists at the University of Washington have shown that bacteria in the branches of poplar trees can also fix nitrogen. Science Daily says that the microbiome is highly diverse, able to deliver fixed nitrogen to the tree, with no root nodules required. “This could have significant implications for common agricultural crop plants,” the article says. “The microbes the team has isolated from wild poplar and willow plants help corn, tomatoes and peppers, as well as turf grasses and forest trees to grow with less fertilizer.” Plant microbiologist Sharon Doty was intrigued by wild plants thriving in rocky, sandy soils with few nutrients. She looked at the potential of microbes for improving agriculture:

Fertilizers are synthesized using fossil fuels, so costs can fluctuate wildly. Because fertilizers are used for growing everything from agricultural and bioenergy crops and trees for lumber to the grass in golf courses, this volatile pricing and uncertain availability affects everyone.

Having access to the key microbial strains that help wild plants thrive on just rocks and sand will be crucial for moving agriculture, bioenergy and forestry away from a dependence on chemical fertilizers and towards a more natural way of boosting plant productivity,” Doty said.

Agricultural scientists in Australia are looking at a different approach to reducing dependence on commercial fertilizers. Two scientists are studying columella cells that grow at the tips of roots, seeking to determine the epigenetic factors that regulate their uptake of nutrients from the soil. PhysOrg points out that numerous cell types exist in roots, with complex interactions. “On top of the genetic code within these cells sits another code, known as the epigenome, which can direct which genes are switched on and off,” Tim Stuart of the University of Western Australia says. “While epigenetic patterns across different plant organs and tissues have previously been studied, this is the first finding of differences between individual cell types of the root.”

Given their country’s history of famines, Chinese scientists are also very interested in agricultural productivity. In PNAS, a paper looks at more detail into the symbiosis between plant and nitrogen-fixing bacteria. Plants send chemical signals to the bacteria, encouraging the growth of root nodules and stimulating nitrogen fixation. “Our results,” they say, “provide a mechanism for facilitative root–root interactions explaining how species diversity may enhance ecosystem productivity with important implications for developing sustainable agriculture.”

Our natural human inclinations are often wasteful and impulsive. Wanting a quick return, we use fossil fuels to create fertilizers that pollute the atmosphere and land. We spread aluminum sprinkler systems over many acres to give our crops artificial rainfall. If a desert plant can grow out of dry sand, and a tree out of bare rock, they can teach us a thing or two about sustainable agriculture.

Notice that two of our heroes of creation science, George Washington Carver and Gregor Mendel, performed their most important work with peas and peanuts—two members of the legume family. When Carver prayed for wisdom, asking “Mr. Creator, why did you make the peanut?” he was rewarded for his inquisitive mind into the wise purposes of God with a series of discoveries that still astonishes scientists today.

Those who deny the Creator’s purposes court disaster. Trofim Lysenko rejected Mendelian genetics on ideological grounds. Though he also disputed some of Darwin’s ideas, he was a materialist and evolutionist. The famines that resulted from his flawed ideas killed millions.

Moses said it is the Lord who gives us the power to make wealth. A portion of that power comes in the rationality with which He endowed mankind to use as good stewards of the earth, seeking to understand the designs around us for insight, application and the pursuit of happiness.  Carver didn’t get an audible response from Mr. Creator to his question. He got inspiration to apply his rationality in the lab to find the answer, and came up with 300 uses for peanuts.

We believe the path to productivity is asking, like Carver, the “why” question, assuming God had a wise purpose in the way he set up the natural economy. The goodness of God is hereby evident to all people, even foolish Greeks who worshiped idols. Paul told the men of Lystra that the Creator did not leave himself without witness: “He has shown kindness by giving you rain from heaven and crops in their seasons; he provides you with plenty of food and fills your hearts with joy” (Acts 14:17). That common grace has a purpose: “We are bringing you good news, telling you to turn from these worthless things to the living God, who made the heavens and the earth and the sea and everything in them.”

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