Latest Tutorial on Efficient Walnut Planting Techniques and Methods

Cultivation of Walnut Seedlings

To ensure the seedling quality for walnut base afforestation and avoid the quality variation caused by using local walnut seedling propagation, efficient and rapid propagation and grafting techniques are adopted to cultivate grafted walnut seedlings, that is, using one-year-old iron walnut seedlings for in-place rootstock or transplanted rootstock grafting to cultivate grafted walnut seedlings. Its main advantages are:

1. It can well maintain the excellent traits of the mother plant and accelerate the achievement of improved walnut varieties.

2. It can significantly increase yield and improve quality.

3. It can dwarf the plant and bring fruiting earlier.

4. It can make full use of iron walnut germplasm resources.

Planting of Walnuts

Walnut planting begins with the selection of the planting site. Flat land, terraced land and gentle slopes are chosen as walnut planting bases, and full or block site preparation is carried out. Planting should ensure large holes, spread roots, close contact between roots and soil, full backfilling of pond soil, sufficient watering, heat and moisture preservation, and adequate nutrients, so as to ensure the survival of walnut planting and facilitate the rapid growth of walnut trees. In order to master practical and feasible walnut planting techniques, the forestry department has, through years of exploration, obtained very good experience, referred to as the “six ones” technique of walnut planting, namely “choose a good piece of land, dig a large pond, put in a load of farm manure, plant a strong seedling, water a bucket of clear water, cover a piece of plastic film”.

1. Site Selection

Choose relatively concentrated and contiguous land such as flat land, terraced land and gentle slopes with loose soil and good drainage as the walnut planting base. It grows best on calcium-containing slightly alkaline soil. Walnut is a deep-rooted tree species, and its root system requires a deep soil layer of more than 1 m to maintain good growth and development. If the soil layer is too thin, it is easy to form “little old man trees”, or the shoots wither year after year, and no yield can be formed.

2. Site Preparation and Planting

Seedling planting is an important foundational task for establishing a walnut base. Every planting step must be well controlled to improve the survival rate and planting results.

① Site preparation: Digging planting ponds in advance is conducive to soil maturation and increased water content in the planting ponds. Digging planting ponds can be done as early as summer. The specifications of the pond are length × width × depth of 100 cm × 100 cm × (80—100) cm. After the pond is dug, backfill it layer by layer with topsoil and then leaves and weeds (or organic fertilizer) until it is close to the ground surface, with a slight groove to facilitate water accumulation. The backfilled pond is left until planting time. In places where conditions do not allow digging ponds in advance in summer, ponds can also be dug and planted on the spot before planting. The pond is 100 cm long and wide, and 80—100 cm deep. When digging, pile the topsoil and subsoil (or stone) from the pond separately. If the soil is clayey or the lower layer is gravel or an impermeable layer, the planting pond should be enlarged and deepened, and guest soil should be used for improvement. When returning soil to the pond, mix 25—50 kg of farm manure (stable manure, green manure, compost, etc.) and 1 kg of ordinary calcium superphosphate or 1.5 kg of calcium magnesium phosphate fertilizer with the topsoil for each pond, then fill it into the pond. If farm manure is lacking, leaves, weeds, turf soil, organic garbage, etc. can be used instead. The positions of the ponds are generally arranged horizontally, that is, each row is on the same horizontal plane.

② Planting season: As the saying goes, “Plant trees early, do not wait for spring dawn.” The time for planting walnuts should be after the seedlings enter dormancy in late autumn or before the seedlings sprout in late winter and early spring, that is, from the ninth lunar month to the first lunar month of the following year. Planting is not suitable during the vigorous growth period in summer.

③ Planting method: The walnut planting method is generally determined according to the mountain situation and terrain. Where the mountain situation is gentle and the slope is not steep, rectangular planting can be used; if the slope is steep and the terrace surface is narrow, a triangular arrangement is preferable.

④ Planting density: 12—16 plants per mu is suitable. On flat land, the spacing between plants and rows is 7 m × 8 m or 6 m × 9 m, about 12 plants per mu; on sloping land, the spacing between plants and rows is 6 m × 7.5 m or 6 m × 7 m, about 15—16 plants per mu. Usually, walnut plots intercropped with crops have better results, using cultivation instead of tending, and using short-term crops to support long-term crops, so that walnuts are produced above and grain is produced below, achieving multiple benefits from one effort, and only then can high yield and high quality be obtained.

3. Planting Techniques

Planting techniques can be summarized as the eighteen-character formula: “place upright, direction, stand straight, cover with soil, lift gently, tread firm, make a basin, water, cover with film”.

① Place upright: When planting, place the seedling in the center of the prepared pond, aligned front, back, left and right.

② Direction: Set the seedling in the direction it faced before transplanting.

③ Stand straight: Hold the seedling straight and let the root system spread out in all directions.

④ Cover with soil: Cover with nutrient soil mixed with fertilizer.

⑤ Lift gently: After the root system is completely covered, gently lift the seedling once so that the root system spreads out and closely combines with the fine soil, then gradually fill in soil. The planting depth should be such that after the soil settles, it is consistent with the depth at which the seedling was buried in the original nursery.

⑥ Tread firm: During the soil filling process, tread while filling, tread once for each layer of soil filled, until the soil is filled to 5—10 cm above the ground surface.

⑦ Make a basin: Build a ring-shaped soil ridge around the pond.

⑧ Water: Water sufficiently to set the roots, 50—80 kg per plant.

⑨ Cover with film: Cover each plant with 1 piece of agricultural plastic film measuring 1 m × 1 m. Cut a small hole about 6 cm in diameter in the center of the film, let the seedling stem pass through it, and after it lands, cover the small hole with fine soil on the film, and bury the edges below the ground surface soil.