Peanut Grass (Arachis pintoy) as Erosion Control


Peanut Grass (Arachis pintoi) as Erosion Control

 


Description and Rationale

 

 

Erosion of soil is a common problem in the Philippines. Erosion of top soil can occur when a raindrop that falls, hits the soil, and splats spreading the soil. It then creates mud that runs. This motion is hard to control but is there a way to prevent it? If the side of a hill is eroded away, a landslide can occur and the side of the hill will just wash away. That dirt will never be recovered. How can we prevent erosion from happening?

 

There are land slides and top soil washing away all the time. Have you ever taken a trip to Banaue at Christmas time? You will find that you have to take detours around landslides that have taken place because wet season rainfall. Banaue is a popular tourist attraction. What if the tourist can’t get there? How is that going to affect the livelihood of the people who live there and depend on the tourist that were blocked by the land slide? What if a landslide falls on a car? What is going to happen if all of the top soil washes away? Will farmers be able to grow crops? Will the quality of the crops be good enough to feed the nation? Can erosion be prevented or is it a force of nature that we can’t control?

 

Erosion is happening all around you. Have you ever looked out the window of your car as you are driving down the street during a hard rain in rainy season? Look at the brown water all around you. What you are seeing is erosion and the brown in the water is the top layer of soil that was washed away with the high waters. There might be new ways of saying saving it. If you could find a plant whose roots stabilize the soil used along with terracing the soil to prevent erosion, the people could garden in the spaces between the plants. They can help the environment and find a means of livelihood at the same time.

 

The purpose of this project will be to research erosion and what are the main factors in the process of erosion through interviewing people who work on preventing erosion and literature already written. These resources will direct us in the experimental phase where key variables in erosion will be further explored and if there is a way that to help prevent erosion.

 

Three possible ways to control erosion could be using mulch, terracing the dirt with the flow of the land and finding plants that have a root system to hold onto the soil. This could help stop the fertile top soil from being washed away. Once it is gone it is gone.

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Biology

 

Common Names and Synonyms

 

 

 Arachis pintoi is also called the “pinto peanut.” Other names synonyms include “wild peanut” (Philippines) and “peanut grass.” It is called the “thua lisong tao” in Thailand and the “kacang pinto” in Indonesia. It is also called the “amarillo forage peanut.”

 

Classification

 

 

Kingdom:

Plantae

Division:

Magnoliophyta

Class:

Magnoliopsida

Order:

Fabales

Family:

Fabaceae

Subfamily:

Faboideae

Tribe:

Aeschynomeneae

Genus:

Species:

Arachis

Arachis pintoi

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Morphology and Physical Description

 

 Like the names states, the A. pintoi is a relative of the Arachis hypogaea (peanut) but unlike the peanut, after it is established it takes little maintenance to reproduce. The pinto peanut is a low growing, perennial legume. The leaves of the plant can be as big as 4.5cm x 3.5cm. Its 20cm tap root system is great for erosion control and it can spread under ground even under heavy grazing. The standard flower size is a 12-17mm flower. The flower is yellow. If planted and let grow, they can rapidly cover a wide area making a carpet appearance of their dark green leaves. It is generally found on red, sandy-bottom soils of low to moderate fertility and high aluminum saturations particularly in low areas in which the ground is wet to flooded during rainy season.

 

 

Getting Food

 

 

A. pintio like all plants is an autotroph. This means that the plant captures part of the energy in the light and transfers it into usable energy through the process of photosynthesis. Photosynthesis involves a series of chemical reactions in which one reaction triggers another. The linkage is called a biochemical pathway. In using the biochemical pathway, they manufacture organic compounds from carbon dioxide and water and then during conversion, the plant’s waste gas, oxygen, is released.

 

The best growing conditions are in well-drained and moderately fertile soil. It is limited by moisture in all situations and is limited by the day length and temperature in the subtropics.

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Reproduction

 

The A. pintoi flowers throughout the growing season. The flowering is apparently dependent upon the dry-wet cycle. The plant spreads underground at a rate of up to 2 meters a year in the tropics. Seed is produced on pegs developing from extensions of the ovary, placing the seed in the ground, mostly in the top 7 cm.  Pegs vary in length from 1-27cm long.  Pegs do not penetrate hard, dry ground and shrivel and die on contact with the soil.  In the upland tropics, it normally takes about 6 weeks from flowering to mature pods towards the end of the growing season, although this may occur in mid-season in the tropics.

 

Environmental Factors

 

The best climate for growth of the pinto peanut is in the warm rainy seasons and in a sub tropical lowland environment. It can grow in higher elevations and can withstand a dry season of four months. It grows the best with a rainfall of over 1100 mm per annum. It also grows well in well-drained sandy or clay soils with a low natural pH and low to high fertility. It has some drought tolerance. It grows best in temperature of 22o C to 28o C.

 

Diseases cause no long-term damage but rats and mice that are attracted to the nuts can be a pest. It does not grow well with aggressive grasses but grows well under trees. It is however vulnerable to some fungal diseases which include various leaf spots and black stem lesions.

 

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Origin and Distribution

 

A. pintoi originated from the valleys of the Jequitinhonha, Sao Francisco, and Tocantins river valleys in Central Brazil. It has since been introduced to the United States, Australia, countries in Central and South America, the Pacific, and many countries in Southeast Asia where there is a warm rainy season and easy living conditions for them. They have had a great influence on soil fertilely and erosion control through out the world.

 

 

Importance to People

 

The A. pintoi has been introduced in many subtropical places where it has been used as a cover crop and has been used in pastures for grazing. It has great value in that it is a legume that adds fertility to the soil and will hold onto the soil to help erosion. It can thrive under heavy grazing which makes it a ideal plant for ranchers to plant in their pastures. If grown to its maximum height, it can also be cut and used as hay for feeding livestock.

 

In places like the Philippines it could be a vital crop to be planted. It reproduces quickly and is resistant to four months of hot season. It will hold onto the soil during a rainy season and it can withstand short floods. This could reduce the amount of mudslides that block roads as a result of heavy rain. Philippine traffic is bad enough without these obstacles blocking the road.

 

Since it is such an easy crop to grow farmers will use it to plant in between their crops to add nutrients to the soil. If they are growing trees, they can plant it in between the trees to prevent erosion.

 

 

Survivability and Endangered Status

 

The A. pintoi can easily survive because it reproduces easily and is not affected by heavy grazing. It can survive in many different types of climates and under many different circumstances.

 

The pinto peanut is not endangered and there is little chance of it becoming so in the near future because there are also no long term diseases that will weed out the entire species. Since it is hardy, it puts nitrogen back in the soils, and it helps prevent soil erosion, it should continue to thrive in the tropics and subtropics.

 

 

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Potential Solutions

 

Possibility 1

 

TERRACING WITH ARACHIS PINTOI ON ROADSIDES

 

The benefits of using a terracing system with a hedge row to prevent erosion is that there is little cost because all of the material being used while making these terraces is organic and can easily be found. I have done an experiment on the Faith hillside by the pool parking lot in which this terracing system is being used to prevent soil erosion and the washing away of the pool parking lot. I simulated a rain fall by poring seven liters of water down the section of the hill where the Arachis pintoi was growing and catching the runoff. I repeated the same process on the far edge of faith property on the same hill where there were no plants growing. After catching the water I let the water settle so I could see how much soil had eroded away from each spot. I then dumped out the water with no dirt and took the dirt out to look at it. The spot that had no plants had eight to ten times more dirt collected than the spot where the Arachis pintoi was growing.

 

 

 

Advantages:

  1. The Arachis pintoi acts as a buffer between the falling rain and the dirt to help slow down the momentum of the water.

  2. Like the Arachis pintoi is anchored in the ground, Psalms 1:1-3 tells Christians to meditate on the law day and night. We are to be anchored and know God’s Word. If Arachis pintoi is correctly handled and grown, it will be a solid foundation and will not easily be gotten rid of. The Bible says in II Tim 2:15-19 that Christians should not be ashamed and should correctly handle the word of God to build a solid foundation for their Christianity.

  3. It is cost efficient because cuttings can be used as a way to get the Arachis pintoi started and once started; it will naturally grow by itself. (Cuttings are made by cutting a stem into four or five sections and planting it into the ground. The plant will then shoot out roots into the soil to anchor the stem and then begin to grow.)

  4.  

 

Disadvantages:

  1. It will require getting enough plants to plant on the side of the roads. There are miles and miles of roads that are sometimes almost impossible to travel on because of mudslides.

  2. The labor cost of planting enough of the plant to make a difference in the road conditions.

  3. The Arachis pintoi grows fast but it only helps with the top layer of soil. There will also need to be trees with deep root systems to keep entire hills from washing away and trees take time to grow.

  4. It may spread into fields where it may not be welcomed because it grows so easily.

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Possibility 2

 

PASTURES WITH ARACHIS PINTOI FOR ANIMAL FEED

 

With its outstanding ability to grow, the Arachis pintoi can be planted in hilly pastures to prevent erosion.

 

Advantages:

  1. It will prevent erosion of hillsides that it is growing on and it will feed livestock or ranchers at the same time.

  2. If rotational grazing is used (dividing a field into sections and only letting the animals in one section at a time to allow plants to grow back after being eaten by livestock) the rancher will be able to get maximum use from his fields.

  3. The Arachis pintoi will spread rapidly and is easy to grow in moist conditions by using the process of cuttings.

Disadvantages:

  1. When livestock graze the whole field at once, they have tendency to stick to one spot and only eat the plants that are in that spot while leaving the other plants alone. This will eventually lead to the death of the Arachis pintoi in the over-grazed section, and cause it to begin to erode. When moved after minimal grazing, the plants will be able to recover while the next section is being grazed.

  2. It does not withstand heavy traffic (does not grow well in places where animals or people usually walk). Cows for instance like to walk on level ground to balance their bodies. They will find a path that is level and most of the herd will follow the same path. If you have planted the Arachis pintoi in the field, the plant will die in the path where the cows walk. This will result in soil erosion where the path is because there is no buffer between the falling rain and the dirt.

 

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Possibility 3

 

GROWING ON A FRUIT FARM IN BETWEEN THE FRUIT TREES

 

Growing the Arachis pintoi on fruit farms to prevent erosion while putting nutrients back in the soil for the fruit trees to fertilize the soil while they are growing and producing fruit.

 

Advantages

  1. The Arachis pintoi keeps the good top soil from eroding away around the trees and the trees have deep tap root systems that will hold onto the dirt farther down in the soil below the Arachis pintoi’s roots. The Arachis pintoi will help prevent surface erosion and the fruit tress will help prevent mud slides.

  2. The fruit trees will be provided with nitrogen in the soil for growing because the Arachis pintoi, being a legume plant, has the ability to put the nitrogen back into the soil that is lost while the fruit trees are growing.

  3. The Arachis pintoi will slow down the growth of weeds around the fruit trees. This is good because then it will require less labor to maintain the field. The farmer can be off working in a different field to maximize his productivity and not have to use as much labor to maintain his field with the Arachis pintoi in it.

Disadvantages

  1. Some types of weeds will be able to grow in the Arachis pintoi. This will result in manual labor to remove the weeds.

  2. If the soil is constantly wet, some molds may start to grow on the Arachis pintoi’s roots.

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Bibliography

 

Gallegos, Epigmenio. "Improving a native pasture with the legume arachis pintoi in the humid tropics of Mexico." 10 Sep 2003 110-131. 19 Mar 2006 <http://library.wur.nl/wda/dissertations/dis3422.pdf>.

 

Ian, Partridge. "Pinto Peanut." Better Pastures for the Tropics and Subtropics. 25 Mar 1998. tropical grasslands. 19 Mar 2007 <http://www.tropicalgrasslands.asn.au/pastures/arachi.htm>.

 

Mannetje, Len't. "Arachis Pintoi." (1996 1-5). 19 Mar 2007 <http://www.architecture-projectmgmt.com/pics%20z_oasfactsheet/0301Archis%20pintoi.pdf>.

 

Musen. Personal interview. 06 May 2007

 

Rivas, L., F. Holmann. "Early adoption of Arachis pintoi in the humid tropics." 12 Apr 2000 19 Mar 2006 <http://www.cipav.org.co/lrrd/lrrd12/3/riva123.htm#Livestock%20Research%20for%20Rural%20Development,%20Volume%2012,%20Number%203,%202000>.

 

"Arachis Pintoi." Tropical Forages. 19 Mar 2007 <http://www.tropicalforages.info/key/Forages/Media/Html/Arachis_pintoi.htm>.

 

"Perennial Peanut." Cover Crops: Legumes . 05 Jul 2002. Sustainable Agriculture in Hawai'i. 19 Mar 2007 <http://www.ctahr.hawaii.edu/sustainag/CoverCrops/perennial_peanut.asp>.

 

"pinto peanut." Plants Profile. o5 Jun 2007. United States Department of Agriculture. 05 May 2007 <http://plants.usda.gov/java/profile?symbol=ARPI8>.

 

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