Compostagem do resíduo sólido gerado na cultura do fumo (Nicotiana tabacum L.) e sua utilização para produção de mudas arbóreas

Abstract

This study aimed to achieve organic compost from solid waste generated by the tobacco harvest and its evaluation in the production of tree seedlings. This work was developed in three stages. In the first stage, the experiment was carried out in a entirely random design with six repetitions with the following treatments: TF+EB+RB-chopped tobacco stem (85%)+bovine manure (15%)+bovine rumen (0,26%); TF+EB+MP-chopped tobacco stem (85%)+ bovine manure (15%)+microsept-dust (0,13%) and TF+EB-chopped tobacco stem (85%)+ bovine manure (15%). It was evaluated the temperature, moisture content, C/N relation and pH. The temperature and moisture content of the piles were weekly monitored. The piles sere revolved each 07 days, initially, and then each 14 days until the 60th day. Between the 20 and 40 days, the piles kept a temperature from 57 to 60 ºC. The mixture containing bovine rumen (RB) presented the lowest temperature after 40 days. At the end of the composting, the mixture containing microsept-dust (MP) was those which presented the lowest moisture content average. The C/N relation, of the achieved compost, ranged from 10/1 to 11/1. The three treatments presented pH slightly alkaline in the maturation process, being the 60 days considered to be time enough to obtain an organic compost of tobacco waste using bovine manure and rumen. In the second stage, the combinations of tobacco stems and bovine manure and rumen (TF+EB+RB); tobacco stem, bovine manure and microsept-dust (TF+EB+MP) and tobacco stem plus bovine manure (TF+EB) were chemically evaluated. Analyses of the organic compost were carried out to determine the concentration of macro and micro nutrients, nicotine concentration and presence of pesticides or herbicides residues. It was noticed a high concentration of potassium (K), nitrogen (N), chlorine (Cl) and iron (Fe) comparing to the other micro and macro nutrients. Residues of herbicides and pesticides analyzed in the raw material (TF) were not detected, neither the presence of nicotine in medium samples of the compost achieved after 120 days. In the end of the composting process it was noticed that the treatment containing bovine rumen and manure and the one containing only bovine manure were those which provided organic compost with the highest level of micro and macro nutrients. Stage 3. The experiment was carried out in a woven nylon covered lath house in an experimental design of random blocks in a factorial schema with four treatments and seven repetitions. It was evaluate the compost T1- chopped tobacco stem (85%) composted with bovine manure (15%) and bovine rumen (0,26%); T2- chopped tobacco stem (85%) composted with bovine manure (15%) and microsept-dust (0,13%); T3- chopped tobacco stem (85%) composted only with bovine manure (15%). The parameters evaluated were germination, caulis diameter and height, root length, nodules fresh mash, fresh and dry mass of the aerial part and of the root, and number of nodules (Erythrina sp.). The mulungu (Erythrina sp.) and amburana-de-cheiro (Amburana sp.) seeds presented a germinative percentage of 100% on the 20 days of sowing. The pitomba (Talisia sp.) and the jenipapo (Jenipa sp.) presented germination percentage of 100% and 96%, respectively, but 30 days after the sowing. The statistic results showed that the compost 1 and the compost 3 provided best average values to the parameters growth in the four studied species when comparing to the others. The average values achieved statistically about the fresh and dry mass of the aerial part and roots of the plants were also more expressive to the organic composts 1 and 3. The organic compost obtained with the tobacco cultivation waste, mixed with bovine manure and rumen or only with manure provided better effects in the growth, dry and fresh mass to the four forest species studied.