Detailed Explanation of Soil Management Techniques for Schisandra Berry Orchards

In nature, soil is the foundation for plant growth and fruiting, and the source of water and nutrient supply. When the soil is deep, loose and well aerated, soil microorganisms are active and can improve soil fertility, which is beneficial to root growth and enhances metabolism, and plays an important role in strengthening tree vigor and increasing yield per unit area and fruit quality. Therefore, for pollution-free standardized cultivation of Schisandra berry, soil management is an important part. The soil management of Schisandra berry means correctly carrying out fertilization, irrigation and between-row management according to its growth and development characteristics and nutritional status, thereby ensuring high, stable yield and high quality, high efficiency.

1. Main nutrients required by Schisandra berry and seasonal changes in their levels

(1) Nitrogen When nitrogen supply is insufficient, the new shoots of Schisandra berry grow weakly, the leaves are small and pale, vegetative growth ends prematurely, the fruit clusters and berries are both smaller, and yield decreases noticeably. When nitrogen is excessive, branches and leaves grow excessively and are not solid, and the plant is susceptible to disease. In one year, the absorption of nitrogen by Schisandra berry roughly begins at the same time as bud break, and the demand for nitrogen is greatest from leaf expansion to before the flowering period. Therefore, nitrogen fertilizer application should focus on the early growth stage, so that the plant can form robust new shoots and well-developed flowers in the early growth stage, laying a good foundation for fruit set and fruit growth.

(2) Phosphorus Schisandra berry absorbs phosphorus from the time new shoots begin to grow in early spring until the berry ripening stage, with the greatest absorption during the vigorous new shoot growth period and the berry enlargement period. During berry ripening, large amounts of phosphorus in the stems and leaves are transferred to the fruit.

After phosphate fertilizer is applied to the soil, it is quickly fixed, moves very slowly in the soil, and is not easily lost, so phosphate fertilizer can be applied together with base fertilizer. To improve fertilizer efficiency, it should be applied appropriately deep and close to the root system. If phosphorus needs to be supplemented during the growing season, 0.3%-0.4% potassium dihydrogen phosphate can be used for foliar spraying.

(3) Potassium Schisandra berry absorbs potassium throughout the entire growing season, but as the berries enlarge, potassium absorption increases noticeably.

After potassium fertilizer is applied, it is not easily fixed by the soil, so it should be applied appropriately deep and close to the root system, with two topdressings per year, the first in early May (bud break period), and the second in the middle growth stage of the plant (early July). Apply 10-25 grams of potassium sulfate per plant per year; during the critical period of flower sex differentiation (late June to early July), 0.3%-0.4% potassium dihydrogen phosphate can also be used for foliar topdressing.

(4) Calcium Calcium is an element with relatively high content in the Schisandra berry plant, mainly in old leaves, and its content in branches and leaves shows an increasing trend throughout the year (mainly from late May to October). Calcium can transform nitrate nitrogen, so when calcium is deficient, nitrogen deficiency is often likely. When calcium is adequate, fruit quality can be improved.

(5) Magnesium Magnesium is the main element constituting chlorophyll. Its content in the leaves of Schisandra berry also changes with the seasons, showing an increasing trend from late May to October, especially with relatively high content in October. This is particularly obvious from leaf color: the leaves are dark green and glossy, which helps the plant carry out photosynthesis and accumulate nutrients.

(6) Zinc Zinc is related to oxidation-reduction processes and is an important element in plant respiration, and it has the effect of increasing fruit set rate and yield. When zinc is deficient, spots or yellowing appear on the leaves.

(7) Manganese Manganese is related to oxidation-reduction in the plant body and has an important effect on chlorophyll formation. Manganese can promote the formation and transfer of sugars, enhance respiration and photosynthesis, and also benefit root formation. When manganese is adequate, it can promote growth and fruiting and help increase yield.

The fertilizer effects and functions of different fertilizers, as well as fertilization principles, are shown in the appendix.

2. Fertilization

(1) Autumn fertilization Apply 3-5 m³ of farmyard manure per mu. Starting from a one-year-old orchard, carry out trench fertilization every other year on both sides of the trellis surface at a distance of 0.5 m from the plants, and thereafter take turns opening trenches outward along the outer edge of the previous fertilization. The trench is 0.4 m wide and 0.3-0.4 m deep. After fertilization, fill back with soil and level it, until farmyard manure has been applied throughout the entire orchard.

(2) Topdressing Topdress twice each year. The first time is at bud break (early May), applying quick-acting nitrogen fertilizer and potassium fertilizer; the second time is at the middle growth stage of the plant (early August), applying quick-acting phosphorus and potassium fertilizers. As the tree body expands, the fertilizer amount increases year by year: ammonium nitrate 25-100 grams per plant, superphosphate 200-400 grams per plant, and potassium sulfate 10-25 grams per plant.

(3) Foliar fertilization The root system of Schisandra berry is relatively underdeveloped. Berry enlargement, new shoot growth and flower bud differentiation all consume relatively more nutrients and easily cause nutrient competition. Therefore, timely foliar spraying during key periods of plant growth, such as the berry enlargement period and the critical period of flower bud differentiation, has positive significance for ensuring normal plant growth and high, stable yield.