RESUMO
Mechanization in carrot harvesting is essential to save time and reduce labour-intensive work as well as harvesting costs. The aim of the study was to determine the soil properties and plant parameters for designing an appropriate carrot (cv: Madhuvan) harvesting machine, that would address the challenges faced by farmers. The physical characteristics of the soil and carrot plants significantly influence the design of the digging, conveying, de-topping, and collection units. These parameters include the digging depth, blade angle, forward speed, plant catch height, conveyor belt spacing, conveyor speed, and collection unit size. The mean values of shoot length, root length and shoot diameter at top of carrot were 62.5 cm, 26.5 cm, and 3.72 cm, respectively. The average weight of carrot root was 61.85 g. The mean values for spacing between ridges, height of ridge and width of ridge were 44.3 cm, 12.1 cm, and 42.8 cm, respectively. The mean number of carrots per meter row length was observed as 41. The black cotton soil with a mean moisture content of 19.77% (d.b.) at the harvesting stage of carrot, and its bulk density measured 1.31 g cm-3, while the average value of soil resistance was 2153.5 kPa. By utilizing this data, the machine's design can be fine-tuned to ensure effective digging performance while minimizing any potential damage to the carrot roots during the harvesting.
RESUMO
The least limiting water range (LLWR) and degree of compactness (DC) can be useful indicators of soil physical quality and crop yield. This study focused on assessing of LLWR, DC and evaluation of critical values to crop growth of an Alfisol and Oxisol under no-till management. Undisturbed soil cores were taken from the layer 0.00 - 0.20 m depth. Soil water retention curve, soil penetration resistance curve, air-filled porosity and bulk density (Bd) were measured. The range of LLWR variation was limited by volumetric water content at field capacity and penetration resistance. Values of LLWR varied from 0.00 - 0.14 m3 m-3 to Alfisol and 0.00 - 0.04 m3 m-3 to Oxisol. The critical values of the Bd and DC for crop development were 1.79 Mg m-3 and 1.35 Mg m-3 and 96% and 74% to Alfisol and Oxisol, respectively. Further researches relating LLWR, DC and crop response are still required in soils with different conditions and management.
O intervalo hídrico ótimo (IHO) e o grau de compactação (GC) são indicadores úteis da qualidade física do solo e produção de culturas. Objetivou-se avaliar o IHO, o GC e valores críticos do crescimento de plantas de um Argissolo e Latossolo sob semeadura direta. Amostras indeformadas de solo foram coletadas na camada de 0,00 a 0,20 m. Avaliou-se a curva de retenção de água e de resistência à penetração, a porosidade de aeração e a densidade do solo (Ds). A amplitude de variação do IHO foi limitada pela umidade na capacidade de campo e pela resistência à penetração com valores de 0,00 a 0,14 e de 0,00 a 0,04 e m3 m-3 para o Argissolo e Latossolo, respectivamente. Os valores críticos ao desenvolvimento de plantas de Ds e GC foram 1,79 e 1,35 Mg m-3 e 96% e 74%, respectivos para o Argissolo e Latossolo. Pesquisas futuras relacionando IHO, GC e resposta das culturas são ainda necessárias em solos com condições e manejos diferenciados.