Thursday, September 29, 2011


The experience presented has been developing in our small organic farm of one hectare, Bioagricultura White House, located in the Valley of the LurĂ­n River, Pachacamac, district 35 km south of the city of Lima, Peru. We grow a wide variety of products such as cassava (manioc), potato, sweet potatoes (potato), beans, corn, vegetables, banana, strawberry and various aromatic herbs. We also raise guinea pigs (Guinea) for meat and for the recycling of nutrients for the farm.

More than ten years ago, in 1994, we decided to build a bio-digester, Chinese model that at that date had a population of 600 animals to make better use of manure produced by the Guinea Pigs on a farm. To date, the Guinea pig manure was used primarily as compost, already out of directly or mixed with the stubble or crop waste for compost preparation, payment produced under aerobic conditions.

Currently the population of Guinea Pigs fluctuates between 900 and 1000 units and produces us approximately three metric tonnes of manure per month (36 tons per year). It is from this animal biomass produced in the farm - which adds the plant biomass (crop residues) - which promotes recycling. Through these processes we can not only produce bioabonos, in liquid or solid form, but also biogas.
The process that is performed using the bio-digester is somehow a mirror of what happens in nature when buried for millions of years biomass decomposes in anaerobic conditions produces a substantial reservoir of natural gas or biogas.

The bio-digester Bioagricultura White House holds ten cubic meters. The central Chamber has three holes that are connected: a central hole that only opens once a year, for the initial loading and unloading; a lateral hole connected to a tube that goes near the bottom of the camera and serves to regular food, and finally a third hole connected to a side Chamber where the liquid bioabono or biol comes out.

Load initial or load Fund with which the bio-digester feeds each year is composed of a precompost that, in the case of White House Bioagricultura is prepared based on corn stubble and Guinea pig manure. A ton of this precompost, which has three to four weeks of preparation, and with a temperature of between 50 and 55 ° C, is introduced by the central mouth and mix with 200 litres of rumen or from the stomach of cattle pigswill cattle freshly slaughtered; This material is obtained in a slaughterhouse or slaughterhouse in the area, only once a year and usually free because it is considered discard material. Rumen or basofia contains a high burden of anaerobic microorganisms responsible for the fermentation process and the production of biogas, especially methane.

Then adds water to fill a volume of approximately eight cubic meters, leaving the two cubic meters remaining for the storage of biogas in the upper part of the central Chamber of the bio-digester. Immediately comes to close the centre hole with a heavy lid envelope which even placed stones to avoid be lifted by the pressure of the biogas produced.

Weekly feeds the bio-Digester with a mixture of water, and Guinea pig manure in 1: 3 ratio allows us to have a sufficient volume of gas for the entire week.

Within one year of the initial supply of the bio-digester is done downloading, getting solid bioabono or biosol. In the original download is performed by the centre hole is very cumbersome and complicated. To facilitate the downloading of the biosol we have made a modification to the original design of the bio-digester, which consists of the construction of a side window that gives adjacent to the bio-digester ambience and is tightly closed with a subject with pins galvanized iron lid.

The bio-digester Bioagricultura White House comes running efficiently since it was built 10 years ago and thanks to biogas production we have been able to save significantly the cost of electricity in the House.
Once the bio-digester begins to produce biogas (a five or six days), in the summer this energy can be used as fuel in the kitchen or for lighting directly by gas lamps. If you have an electric generator powered by gasoline, prior amendment of the carburetor, it can make it work with biogas (methane) to produce electricity.
We get steadily liquid bioabono or biol, which is not only an excellent organic fertilizer for our crops, but rather by their content of phytohormones, is a valuable activator of growth and flowering of plants, in particular of fruit trees.

The third product in the bio-digester obtained annually to perform the download when collected solid bioabono or biosol, which is an excellent fertiliser for crops.

Given the growing interest by the bio-digesters, each year, when we download the bio-digester and reload it, we offer courses with the motto "learning by doing', in which participants can learn in a very practical way how a bio-digester is built, how it works and how download and then upload.

Without a doubt one of the central attractions of the farm is observed the bio-digester operation as part of the work of recycling we do using all waste the farm produces.