Explanation
1. Crop diversification involves growing a variety of crops. This enhances biodiversity, improves soil health by varying nutrient demands, reduces pest and disease cycles associated with monocultures, and can decrease reliance on chemical inputs, making it an eco-friendly agriculture practice. (Correct)
2. Legume intensification means increasing the role of legume crops in farming systems. Legumes fix atmospheric nitrogen, naturally enriching the soil and reducing the need for synthetic nitrogen fertilizers, which have a significant environmental footprint (energy use, greenhouse gas emissions, water pollution). This is an eco-friendly practice. (Correct)
3. Tensiometer use allows farmers to accurately monitor soil moisture levels. This enables precise irrigation management, preventing over-watering, conserving precious water resources, and reducing the energy consumed for pumping water, thus qualifying as an eco-friendly practice. (Correct)
4. Vertical farming involves growing crops in vertically stacked layers, often indoors under controlled conditions. While it can reduce land use, water use (with recycling), and transportation distances, it often requires significant energy for lighting and climate control, potentially leading to a high carbon footprint depending on the energy source. Its overall classification as universally 'eco-friendly' compared to traditional sustainable methods is complex and context-dependent. (Not considered correct in this grouping as per the likely intended answer scope).
5. Therefore, Crop diversification, Legume intensification, and Tensiometer use are generally considered practices of eco-friendly agriculture.