Detailed Explanation of the Key Points of Suspended Yam Cultivation Technology

Abstract Land preparation: Yams are generally planted at the end of March. Loosen and level the plot and build raised beds. Sleeve pipe production: includes connectors and straight pipes. Substrate production and filling: made by mixing and fermenting mushroom residue, clam shells, Chinese herbal medicine residue and fermentation aids in a certain proportion. Placing the sleeve pipes: Arrange the sleeve pipes filled with substrate into the beds, leaving gaps between the sleeve pipes. Planting: Cover well with plastic film after planting. Water and fertilizer: Drip irrigation once every 3 days. Later management: Trellising, pruning, pest and disease control, harvesting.

I. Preparation Before Planting

1. Land preparation

Yams are generally planted at the end of March. Before planting, the saline-alkali land needs to be loosened and leveled, then raised beds are built, with a bed width of about 3m and a bed spacing of about 0.15m.

2. Sleeve pipe production

(1) The sleeve pipe is a key step in this method. The sleeve pipe includes a connector and a straight pipe. The connector is a PVC plastic pipe with an arc of about 110°, and one end of the connector can be connected to the straight pipe.

(2) The other end is an open port. The straight pipe is composed of 2 semi-elliptical plastic pipes joined together. The straight pipe is about 1.2m long, with an elliptical cross-section and a diameter of 42cm. The straight pipe is equipped with 2 clips, which can be used to tighten the open edge of the straight pipe.

3. Substrate production and filling

The substrate is made by mixing and fermenting clam shells, Chinese herbal medicine residue, mushroom residue, carbonized rice husks and fermentation aids in appropriate proportions, then the prepared substrate is evenly filled into the sleeve pipes. After filling the substrate, the clips can be tightened, and the connectors can be attached.

4. Placing the sleeve pipes

Arrange the sleeve pipes already filled with substrate neatly in the beds, with two symmetrical rows per bed. Appropriate gaps need to be left between the sleeve pipes, with the connector ends facing each other. The spacing between the two rows is about 0.8m. The straight pipes can be slightly tilted, forming an angle of 17-20° with the ground. The top of the sleeve pipes can be covered and leveled with soil. Be sure to cover the pipe ends of the sleeve pipes.

II. Planting

1. First, place the yam seed tubers into the open port of the sleeve pipe connector, then cover the seed tubers with sterile soil having a moisture content of 70-80%, then use black plastic as a plastic film to cover the field plot planted with yams.

2. Above the plastic film, integrated water and fertilizer drip irrigation equipment can be installed. The main pipe is laid at the head of the bed, and the drip irrigation pipe presses down the plastic film. The drip irrigation outlets need to be aligned with each sleeve pipe port, penetrating the plastic film between the drip irrigation outlets and the sleeve pipe ports, so that fertilizer water can drip smoothly into the sleeve pipes during drip irrigation.

III. Water and Fertilizer

1. Yams grow relatively fast. During the seedling stage, drip irrigation is needed once every 3 days, for 2 hours each time. Topdressing can be carried out once every 3 drip irrigations. When topdressing, a special seedling fertilizer (150kg.hm-2) can be used after being completely dissolved in water, and applied with water through drip irrigation.

2. After about 30 days of emergence, they enter the mid-growth stage. Drip irrigation is carried out once every 3 days, for about 4 hours each time. During mid-stage topdressing, topdressing is carried out only after every 2 drip irrigations. A special fertilizer (300kg.hm-2) can be used after being completely dissolved in water, and applied with water through drip irrigation.

3. After yams begin to bud, they enter the vigorous growth stage. Drip irrigation is carried out once every 3 days, for 5 hours each time. During the vigorous stage, topdressing is carried out once every 6 days of drip irrigation. Fertilizer (600kg.hm-2) can be dissolved in water and applied with water through drip irrigation. During drip irrigation, the water output at the drip outlet is 2-3L.h-1.

IV. Later Management

1. Trellising

First, bury cement posts at both ends of the bed, with a post height of 1.8m. After the cement posts are buried deep and fixed, stretch steel wire between the cement posts at both ends of the bed, then tighten it. Thread one end of the yam trellis net onto the steel wire, let the whole piece hang naturally, then thread the bottom line through the lower mesh holes, pull it flat and fix it, and it can serve as a support for yam vines.

2. Pruning

During the growth period, yams need timely pruning of side branches and removal of aerial tubers. Each plant can retain 4-5 side branches.

3. Pest and disease control

During the growth of yam stems and vines, leaf spot disease and anthracnose are relatively prone to occur. Foliar spraying is needed once about every 7 days. For spraying, use 75% chlorothalonil 600-fold solution, 70% mancozeb 500-fold solution, or 50% carbendazim 500-fold solution.

4. Harvesting

Harvesting can begin in mid-to-late October, and all harvesting is completed before the Beginning of Winter. During harvesting, remove the plastic film and the soil above the sleeve pipes, dig out the sleeve pipes along the roots, detach the connectors, then open the clips, and the yams can be taken out. The sleeve pipes can be reused.