Regional
10:50 pm
Tue September 7, 2010

NMSU Professor Patents Liquid Organic Fertilizer

Las Cruces – Even in the harsh region of central Asia, necessity is the mother of invention. It was the needs of farmers in the rugged, impoverished area that inspired a New Mexico State University professor to develop an easily transportable, easy-to-apply fertilizer that could lead to long-term gains for growers the world over.

Zohrab Samani, a professor in the NMSU College of Engineering's civil engineering department, developed a concept for liquid fertilizer while doing volunteer work in 2000 in the Republic of Tajikistan.

"This was just after the civil war in that country, and I was quite distressed with the situation of the farmers who could not afford to buy synthetic fertilizer for their small vegetable plots," Samani said. "It occurred to me that the waste from the large vegetable market in the nearby town of Dushanbe could be used to generate fertilizer."

Inspired, Samani developed a rudimentary accelerated bio-leaching schematic, wherein vegetable waste could be placed in a sealed batch and bacteria-laden leachate was used to hydrolyze and break down the organics into a liquid solution. The idea was to be able to add the solution into irrigation water.

Returning to Las Cruces, Samani went to work in a university lab, developing a liquid fertilizer from grass clippings. He applied the leachate to one of four tomato plants that he was growing at home, and he noticed a sudden surge in the growth of that particular plant.

In 2001, Samani presented his research and findings, along with a proposal, to Abbas Ghassemi, the director of NMSU's Waste Management, Education and Research Consortium, a consortium for environmental education and technology development. Ghassemi offered Samani a mini-grant and Samani used it to help fund additional testing with a column and a recirculation pump, using grass clippings from the NMSU golf course.

During the same time, Samani got together with Marco Huez, a friend who was working towards his doctorate in the College of Agriculture, Consumer and Environmental Sciences. Huez, studying interactions of salinity and organics in chile, began using the liquid fertilizer on green chile being grown in an NMSU greenhouse. The results were astounding, as the liquid-fertilized chiles were measurably larger and more abundant than those in the control group 23 percent higher than previous yields. The organic makeup of the liquid fertilizer had a positive effect on the plants by countering the soil salinity.

"The experiment in the greenhouse showed that the liquid organic fertilizer could increase the yield of green chile, especially in saline soil," Samani said. "It clearly showed that the fertilizer could increase the chile yield under all conditions, and the results were especially pronounced in soil with a high salinity."

Samani and his students kept working, and they developed ways to concentrate the mixture, via cooking it in an oven and through solarization, accomplished by placing the fertilizer in a container, covering it with vented, clear plastic and leaving it in the sun for a few days. Concentrated, the fertilizer's makeup is nutrient-rich liquid, at 6.35 percent nitrogen.

The concoction is convenient, because it can be mixed into drip irrigation systems without plugging the drip tapes. It also is an economical alternative for organic farmers. Fish fertilizer, for example, can cost as much as $7,000 an acre for organic vegetable crops. Using an alfalfa-based liquid organic fertilizer, since alfalfa is grown organically without synthetic chemicals and is readily available, can reduce the cost to $300 an acre. It also can be applied multiple times to one field over one growing season.

Samani and NMSU recently received a patent for the liquid fertilizer and the method used to produce it. He is currently experimenting with ways to temporarily solidify the liquid to make transporting it easier.