Investigation of Soil and Plant Characteristics Relevant to the Design and Operational Parameters of Mechanical Paddy Transplanter

Abstract

Background: Mechanized rice transplanting is crucial in modern paddy cultivation, overcoming labour scarcity and improving crop productivity, but its efficiency depends on soil physical properties, seedling mat quality, and machine operating parameters. Optimal soil and seedling conditions, including soil moisture, texture, and seedling mat strength, are essential for smooth operation and minimizing seedling damage during transplanting. Aims: The study aims to identify the soil and plant characteristics that influence the design and operational conditions of a mechanical paddy transplanter. Study Design: The experimental study evaluated soil and seedling mat characteristics relevant to mechanized transplanting in two different soils. Place and Duration of Study: The experiment was conducted at the Department of Farm Machinery and Power Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, Kerala, India. Methodology: The experiment was conducted in both sandy loam and clay loam soil in a fully saturated state under puddled condition. Soil parameters such as moisture content texture (gravimetric moisture content), bulk density, soil hardness and puddling index were determined using standard laboratory and field methods. The coefficient of friction between soil-metal surfaces was measured to assess tribiological behavior in puddled soil condition. Plant parameters including seedling height, seedling density, height of mat and rupture strength of seedlings were examined for three rice varieties, namely Jyothi, Uma and Sheyas raised in mat-type nurseries at the age of 17-21 days. Results: The moisture content of sandy loam soil was comparatively lower than that of clay loam soil at fully saturated and puddled soil condition. Under puddled field conditions sandy loam soil revealed relatively higher bulk density, whereas clay loam soil showed lower bulk density, implying suitable conditions for mechanical transplanting. Soil hardness for sandy loam soil was comparatively higher than clay loam soil. The puddling index obtained for sandy loam soil and clay loam soil confirmed that the soil well-puddled and fully saturated conditions conducive to transplanting operations. The coefficient of friction observed between soil-metal for sandy loam and clay loam soils obtained were 0.53 and 0.39 respectively. Among all varieties, higher rupture strength value exhibited for separation of cluster comprising three to five seedlings. Conclusion: The findings in the study highlight that seedling age, maintaining optimal soil conditions and fully saturated field with well-puddled condition significantly improve the performance and reliability of mechanical transplanters in both sandy loam and clay loam soils. Among the tested varieties Jyothi exhibited adequate structural integrity and higher rupture strength at the age of 17-21 days makes more suitable for mechanical transplanting.