How to Grow Yam Without Soil in Suspended Air? The Sleeve Tube Technique Is Key
AbstractLand preparation: plant in late March, loosen and rake the plot smooth and build the beds. Sleeve tube fabrication: the key to soilless suspension, including connectors and straight tubes. Substrate and filling: made by mixing and fermenting mushroom residue, clam shells, carbonized rice husk, Chinese herbal medicine residue and a fermentation aid in a certain proportion. Placing the sleeve tubes: arrange the sleeve tubes filled with substrate into the beds, leaving gaps between the tubes. Planting: cover the plot planted with yam with plastic film. Management: trellising, water and fertilizer, pruning and pest and disease control. Harvest: mid to late October.
1. Land preparation
Yam is generally planted in late March. First loosen and rake smooth the saline-alkali plot to be planted, then build the beds, with a bed width of 3 m and a bed spacing of 0.15 m.
2. Making the sleeve tubes
The sleeve tube is the key to soilless suspended cultivation. The sleeve tube includes a connector and a straight tube. The connector is a PVC plastic pipe with an arc of about 100 degrees; one end of the connector connects to the straight tube, and the other end is an open port. The straight tube is formed by joining 2 semi-elliptical plastic tubes; the straight tube is 1.2 m long, its cross-section is elliptical, with a diameter of 6 cm×7 cm. Two clips must be fitted on the straight tube, using the clips to clamp the opening edges of the straight tube tightly.
3. Making the substrate and filling
The cultivation substrate is made by mixing and fermenting mushroom residue, clam shells, carbonized rice husk, Chinese herbal medicine residue and a fermentation aid in proportion. Put the prepared substrate evenly into the sleeve tubes; after the sleeve tubes are filled with substrate, clamp them tightly with clips and fit the connectors properly.
4. Placing the sleeve tubes
Arrange the sleeve tubes filled with substrate into the beds, placing two neat rows in each bed, leaving a small gap between the sleeve tubes. The connector ends must face each other, the spacing between the two rows is 0.8 m, and the straight tubes may be slightly tilted at an angle of 17-20 degrees to the ground. The top of the sleeve tubes must be covered flat with soil, but the tube ports must not be covered.
5. Planting the yam
Place the yam seed at the open port of the sleeve tube connector, then cover the seed with sterile soil having a moisture content of 70%-80%, then cover the plot planted with yam with black plastic film, and build a water-fertilizer integrated drip irrigation facility on top of the film. The main pipe is built at the head of the bed; the drip irrigation pipe can be pressed down onto the film, with the drip outlets aligned with the port of each sleeve tube, then penetrate the film between the drip outlets and the sleeve tube ports, so that during drip irrigation water and fertilizer can drip into the sleeve tubes.
6. Later management
1. Trellising. Place cement posts at the two ends of the bed, with a post height of 1.8 m. After the cement posts are buried deep for fixing, bind and tighten steel wires between the cement posts at the two ends of the bed, then thread one end of the yam trellis net onto the steel wires so that the whole sheet hangs down naturally, then pass the bottom line through the lower mesh holes, and fix the steel wires after pulling them flat, to serve as the support for the yam vines.
2. Water and fertilizer. Yam grows relatively fast. During the seedling stage, drip irrigation is needed once every 3 days, 2 hours each time; after 3 drip irrigations, apply 1 topdressing, dissolving special seedling fertilizer (150 kg.hm-2) in water for drip irrigation. About 30 days after emergence, it enters the mid-growth stage; when watering in the mid stage, drip irrigate once every 3 days, 4 hours each time; after 2 drip irrigations, apply 1 topdressing, dissolving special yam fertilizer (300 kg.hm-2) in water for drip irrigation. In the vigorous growth stage after the yam buds appear, drip irrigate once every 3 days, 5 hours each time, and apply topdressing once every 6 days, dissolving special fertilizer (600 kg.hm-2) in water for drip irrigation, with a drip outlet flow rate of 2-3 L.h-1.
3. Pruning. During the yam growth period, prune side branches in time and remove the yam beans, keeping 5 side branches per plant.
4. Pest and disease control. During the stem and vine growth period, leaf spot and anthracnose are common diseases; foliar spraying may be carried out once every 7 days, using 50% carbendazim 500-fold solution, 70% mancozeb 500-fold solution or 75% chlorothalonil 600-fold solution.
7. Timely harvest
Begin harvesting in mid to late October, and finish harvesting before the Start of Winter. Remove the plastic film and the soil on top of the sleeve tubes, then dig out the sleeve tubes, remove the connectors and open the clips, and the yam can be taken out.