Practical # 1

Practical # 1

Introduction

Low-weight carboxylic acids (LWCAs) are known as agricultural ally important inhibitors or crops (UIbright et al., 1982). Studies showed accumulation of LWCA in natural soils (Stevenson. 1967) and during application of plant materials or green manure followed by water logging (Chandrasekaran and Yoshida, 1973). LWCA ate also found in treated biogenic materials like composts (Bnnton andTrankner. 1999: Himanen and Hanninen, 2011). dig- estates from biogas production (Paavda and Rintala, 2008) and still ages from bio-fuel production (Kaparaju et aL, 2009) that are utilized or have potential to be utilized in agriculture or horticulture and may exhibit phytotoxicity.

LWCA are essential metabolic by-products of microbial degradation or organic matter in aerobic, hypoxic and anoxic conditions (SchiegeL 1986). Among carboxylic acids with one to six carbons, formic acid (Cl) is the smallest by its molecular weight and caproic (C6) the largest. Common for all, their carboxylic group dissociates in water solutions into carboxyl radical and hydronium ion. Degree of dissociation is ion dependent on pKa of the acid and pH of the solution (Harris, 2003). LWCA are volatile or semi-volatile in nature. Henrys law constants range from 1320 to 5530 kg atm mol 'at NmP conditions (Khan and Brimbleoumbe, 1992). So, in addition

Many materials can be used as corrector's acidity. The main ones are: quicklime, slaked lime, calcites lime, crushed seashells, ashes and lime (which is the most used). Both the efficiency and the price are quite varied for each type of concealed (Ringrose et.al, 1994). Concealed with low quality are generally cheaper but in compensation, should be used in larger quantities to correct soil acidity. The increase also increases the cost of transport to the property, as well as the cost of implementing a land area corrected.

Thus, the final cost of correcting soil acidity with a concealed cheap but low quality, may be higher than with a concealed more expensive but better quality. So the concealed more advantageous to the farmer and to be chosen is that which corrects the acidity of your soil at the lowest cost. Thus, the quality and cost position in the farming are the two key points that the farmer should consider in choosing the concealed (Ringrose et.al, 1994).

In most industrialized countries there is a significant decrease in the use of pesticides, without reduction of food production, while in countries like some cities of US, whose economy is expanding rapidly, consumption of pesticides, GMO seeds and improved and chemical fertilizers are in the process of increasing. Several studies show that this causes serious environmental impacts such as pollution of surface and groundwater and imbalances in ecosystem, increases the number of sources of acute toxicity and carcinogenicity for humans human, creates greater dependence on external inputs and can increase the risk of debt farmers. 

Problem Presentation

Soil has basically five components: mineral, organic, water, air and living organisms. In organic production the emphasis is on nutrient cycling within the farming system and the maintenance of soil biological activity, where the organic component has several functions including the ...