Detailed Explanation of Key Techniques for Planting Sichuan Pepper in Three Seasons

I. Selection of Planting Site. Sichuan pepper (Zanthoxylum bungeanum) is a shrub, with a tree height of 2-3 m, a canopy diameter of 2.5-4 m, a root system that can reach a vertical depth of more than 4 m, and a horizontal spread of more than 8-10 m. It has strong adaptability and can be planted on barren hills, barren slopes, terrace ridges, and around houses in areas where the winter temperature is below -20°C. Generally, on sunny slopes and semi-sunny slopes in the middle and lower parts of sloping land, on gentle ridges and mounds, beside terrace edges, and on field edges and ridges in platform-tableland areas, where there is sufficient sunlight, good drainage, and relatively deep soil layers, the Sichuan pepper produced has bright color, a rich aroma, and superior quality.

II. Land Preparation of the Planting Site

1. Timing of land preparation. Land preparation of the Sichuan pepper planting site can be carried out throughout the year, but it is best to complete it before the rainy season, so that during the rainy season it can both store water and preserve soil moisture, and also promote soil maturation and increase soil fertility.

2. Methods of land preparation

(1) Whole-orchard land preparation. Generally, on flat land, regardless of plot size, it is best to use the whole-orchard land preparation method, uniformly deep-plowing 30-50 cm. When deep-plowing, it is best to apply farmyard manure (5000-10000 jin per mu), then harrow and level the ground.

(2) Strip land preparation or hole land preparation. If the planting area is relatively large, strip or hole land preparation may also be used. For strip land preparation, according to the planned planting rows, dig strip trenches 1-1.2 m wide and 60-80 cm deep. When digging the trenches, pile the subsoil and topsoil separately, apply farmyard manure, oil residue, straw, weeds, etc. into the trenches, and fill the trenches level. The method of digging large pits may also be used, that is, after first determining the planting points, dig large pits 80-100 cm square according to the planting points, then apply farmyard manure, fill the pits level, and dig pits again at planting time for planting.

(3) Level terrace land preparation. When planting Sichuan pepper on mountain slopes or gully slopes, carry out level terrace land preparation, generally building level terraces according to contour lines. The width of the terrace depends on the degree of slope: the smaller the slope, the wider the terrace; the greater the slope, the narrower the terrace, but the width must not be less than 2 m. After the terrace is built, dig the planting pits in passing. If conditions permit, apply farmyard manure, backfill, and wait for planting.

III. Planting of Sichuan Pepper

1. Preparation of seedlings. For Sichuan pepper planting, first select high-yield, high-quality seedlings, and require vigorous growth, a complete root system, many fibrous roots, one-year-old stock, seedling height 50-80 cm, ground diameter 0.6-0.8 cm, plump buds, and no disease or insect damage. Sichuan pepper seedlings are best planted immediately after digging. For long-distance transport, packaging in wet burlap sacks or wet straw bags is required. Before packaging, dip the seedling roots in mud slurry, and keep sprinkling water during transport to keep the seedlings moist. Seedlings not planted temporarily should be heeled in in a sheltered, sunny place.

2. Variety combination. Because harvesting Sichuan pepper is relatively labor-intensive, when planting Sichuan pepper on a large scale, attention should be paid to combining early-, mid-, and late-maturing varieties. A single variety has a concentrated maturity period, and if harvesting is not evenly timed, fruit drop will occur. Different site conditions should be matched with different Sichuan pepper varieties. Places with good site conditions should choose the Dahongpao variety, and places with poor site conditions should choose the Xiaohongpao variety.

3. Planting density. Sichuan pepper planting density should be determined according to different site conditions. Generally, on flat land, spacing between plants and rows is 3 x 4 m or 4 x 4 m; on sloping land with poorer conditions, spacing is 3 x 3 m; for field ridges or single-row planting, spacing between plants is 3-4 m.

4. Planting method. Sichuan pepper can be planted in north-south rows in rectangular, square, or triangular arrangements. At planting time, for land that has been prepared, dig planting pits 40-50 cm square; for land that has not been prepared, it is best to dig planting pits 60-80 cm square. If conditions permit, apply farmyard manure, then backfill to a depth of 30-40 cm, and plant the seedlings. When planting, one person holds the seedling while one person fills soil. When half-filled, press around with the foot once so that the roots and soil are firmly combined, then gently lift the seedling upward once so that the root system spreads out. The planting depth should be such that the root crown of the seedling is level with the ground. After the soil is filled level, tread it again, then build a water-storage pit around the pepper seedling. Where conditions permit, water once after planting, and after the water has infiltrated, bury another layer of soil to help preserve moisture. When planting, attention should be paid to aligning plant and row spacing front, back, left, and right, and to leaving production paths and irrigation and drainage systems. In arid and cold areas, when a clump-form tree shape is used, before or after planting, cut back the trunk leaving 5 cm. After planting, mound a soil pile to prevent cold and preserve moisture.

5. Planting period. Based on many years of trials and summary, Sichuan pepper planting has been extended from the previous two seasons to the current three seasons.

(1) Spring planting. Spring planting is carried out after the soil thaws in early spring and continues until the seedlings sprout; earlier is better than later. At planting time, it is best to plant immediately after digging. For long-distance seedling transport and planting, seedling packaging must be done well. After the seedlings are transported back, plant them immediately; those not planted for the time being must be heeled in properly. When spring is dry or soil moisture is poor, water must be given after planting. When conditions permit, cover with plastic film after planting.

(2) Rainy-season planting. Rainy-season planting is a good method tested in recent years to solve the problem of planting Sichuan pepper in arid areas. The planting time is generally from August to mid-October. During cloudy and rainy weather lasting three days or more, dig seedlings with soil and plant immediately after digging. If no sunlight is seen for two days after planting, the survival rate can reach more than 95%. For rainy-season planting, the land should be prepared in advance, weather forecasts should be listened to in time, and the favorable period should be seized for planting. Rainy-season planting should pay attention to the following points: 1) cloudy and rainy weather lasting more than three days; 2) dig seedlings nearby and plant nearby, planting immediately after digging; 3) after planting, pinch off the growing tip; do not cut back the trunk.

(3) Autumn (winter) planting. Autumn (winter) planting is carried out from seedling leaf fall until the soil freezes. After planting, cut back the trunk according to the determined height and do a good job of cold protection and overwintering.