"An Innovative Way For Heating Greenhouses Using Solar Energy During The Winter For Summer Crop Production" - “Wall of water” made of black PE water tubes. "...a simple, sustainable, nonpolluting, no emissions system for growing summer crops in winter by raising the temperature using only solar energy."
Crop rotation is a method used by gardeners to further enhance their vegetable gardens. This technique can significantly increase crop production, prevent exhausting soils, control weed growth, and improve the health of your plants. Go ahead and read the following 3-year plan to get you started on crop rotation. More info at http://homeandgardenamerica.com/simple-crop-rotation-plan
Compost makes a great soil amendment to help your crops grow organically.