Used plastic materials as mulches: An alternative to conventional black plastic mulch for small and marginal farmers

The return of ladies finger (okra) to the joint effect of drip irrigation and mulches is very encouraging. The most common types of mulch are the black plastic mulch (BPM), which is commercially produced by industry but does create environmental problems and increased cost of production particularly for small and marginal farmers. On the other hand, food materials and fertilizers etc. are available and sold in plastic bags. Can we make REUSE of these plastic bags in preparing low cost mulching system for small and marginal farmers? With this in view a field experiment was carried out during the year 2017 at Department of Soil and Water Engineering, Swami Vivekanand College of Agricultural Engineering and Technology & Research Station, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, India. The research experiment was performed in a split plot design on clay loam soil during summer season (February to May) for growing okra. Levels of irrigation were assigned based on crop evapotranspiration (ETc). The effect of four irrigation levels viz. 60% ETc, 80% ETc, 100% ETc and 120% ETc with drip under black plastic mulch (BPM) and different types used plastic material as mulch viz. used reddish rice bag mulch (RBM), used whitish wheat flour bag mulch (WFBM), used white fertilizer bag mulch (FBM) were studied for moderating the temperature, moisture conservation, weed restriction, yield, water use efficiency and cost economics also. Temperature measurement was done with Digital Soil Thermometer at a depth of 7.6 cm and 12 cm at 7: 30 a.m. and 2: 30 p.m. It reflects that used plastic mulches are moderating the temperature at par as BPM. Soil moisture measurement was done with Time Domain Reflectometry (TDR) at 7.6 and 12 cm. Average moisture content under BPM, WFBM, RBM and FBM at 7.6 cm was found to be 27.5%, 25.5%, 26.5% and 26.4% respectively, while it was found to be 23.8%, 21.8%, 22.7% and 22.4% respectively at 12 cm depth. Maximum weed population control (96%) was recorded with BPM followed by used RBM (82%), used FBM (80%) and used WFBM (76%) respectively. The benefit cost ratio was also worked out and found to be higher (2.09) under 120% ETc with BPM as compared to 120% ETc with used RBM (1.86), 120% ETc with used WFBM (1.82) and 80% ETc with used WFBM (1.81). Highest Crop Water Use Efficiency (42.38 kg ha(-1) mm(-1)) was found at 60% ETc with BPM as compared to 80% ETc with BPM (36.72 kg ha(-1) mm(-1)), 80% ETc with used BPM (34.17 kg ha(-1) mm(-1)) and 80% ETc with used WFBM (31.58 kg ha(-1) mm(-1)). From the point of view of initial investment and water saving the 80% ETc with used WFBM is a better choice for small and marginal farmer as the return (1.81) is also closer to the other treatments.