Banca de DEFESA: EDINALDO FRANCO MENDES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EDINALDO FRANCO MENDES
DATE: 27/05/2022
TIME: 09:00
LOCAL: https://conferenciaweb.rnp.br/conference/rooms/leonardo-oliveira-medici
TITLE:

Lettuce cultivation using grass clippings as an alternative substrate in an organic system with automatic irrigation

KEY WORDS:

organic agriculture, plant biomass, nutrient cycling, automated irrigation

PAGES: 91
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Manejo e Tratos Culturais
SUMMARY:

Plant biomass is being widely used in agriculture, mainly as green compost, mulch and composting material to generate organic compost. The Verdeponia organic system (organic cultivation of vegetable crops in pots filled with non-composted plant biomass) is based on the use of grass clippings as a substrate and main or sole source of nutrients for agricultural production with promising results for vegetable crops such as tomatoes and peppers in a greenhouse. The objective of this work was to evaluate the efficiency of this alternative substrate for lettuce cultivation, which has a shorter cycle than the previous ones, considering five irrigation flows. Four independent experiments divided into two cycles were carried out in 3.5 L pots on outdoor benches. Each experiment was carried out in a randomized block design with five treatments and five replications. In the first cycle, two experiments were carried out simultaneously, one with grass clippings (Paspalum notatum) with flow rates of T1-1.85 L/h, T2-1.72 L/h, T3-1.51 L/h, T4-1.32 L/h and T5-1.21 L/h and another with soil fertilized with 10 g of chicken manure per pot with flow rates of T1-3.64 L/h, T2-3.37 L/h, T3-2.87 L/hr, T4-2.41 L/hr and T5-2.16 L/hr. In the second cycle, the two experiments were repeated, in the treatments with grass clippings the flow rates were T1-1.78 L/h. T2-1.68 L/h, T3-1.48 L/h, T4-1.30 L/h and T5-1.20 L/h and not with soil T1-3.43 L/h, T2-3, 16 L/hr, T3-2.72 L/hr, T4-2.35 L/hr and T5-2.12 L/hr. This time, the dose of poultry litter per pot with soil was increased to 25 g and a dose of 5 g of this fertilizer was added to the pots with grass clippings. The variables analyzed were height (H), number of leaves (NF), shoot fresh mass (MFPA), shoot dry mass (MSPA), root fresh mass (MFR), root dry mass (MSR), incidence of chlorophyll a and b (IFC), macronutrient content in leaves and roots of plants, in addition to water use efficiency (EUA). An initial stagnation in plant growth was observed in the experiments with cuttings, with plant recovery occurring at the end of the cycle. It can be inferred that its cause is not due to the lack of nutrients, since it occurred even with the addition of chicken litter in the second experiment with grass clippings. No significant difference was observed between treatments for ICF in any of the four experiments. The nutritional values for shoot, root and substrate were higher in experiments with cuttings than in soil. During the first cycle with grass clippings, significant differences were observed between irrigations. For height H, T4 obtained the best result 15.16 cm. For the number of sheets NF T2 surpassed the others with 27.67. In relation to MFPA, the highest averages were found at the highest flows, indicating greater demand for water in the experiment with cuttings. In the first cycle with soil, the highest average of MFPA was in T2 with 47.87 g, not differing from T3 and T5, this may be a reflection of the higher irrigation depths applied in the soil experiments. In the second cycle, differences were observed between treatments with improvement in plant development, which may reflect the increase in the dose of poultry litter. For MFPA, the highest averages were in T1 with 61.74 g for cuttings and 84.74 g in the soil. The EUA in crops with grass clippings were higher with 3.14 kg m-3 in the first cycle and 3.13 kg m-3 in the second, probably due to the lower initial plant growth. On the ground it was 2.14 kg m-3 and 2.12 kg m-3 in the first and second cycles, respectively. The lower irrigation flows in both experiments showed higher EUA indicating more efficient use of water. Studies indicate potential in the use of grass clippings as an alternative organic substrate for seedling production. New studies should be carried out.

 

BANKING MEMBERS:
Presidente - 2181674 - LEONARDO OLIVEIRA MEDICI
Externo ao Programa - 2136627 - NIVALDO SCHULTZ
Externo à Instituição - CARLOS RODRIGUES PEREIRA - UFF