Ginger has a wide adaptability to soil, and its requirements for soil texture are not strict. It can grow normally on sandy loam, light loam, medium loam or heavy loam. However, loam with deep soil layer, loose soil, rich organic matter and good ventilation and drainage is the most suitable for ginger planting. For example, in Dongwennan Village, Laiwu City, Shandong Province, every household grows ginger with high yield and good quality. It is a well-known professional village and a famous ginger planting center. The characteristics of the soil here are: deep soil layer, suitable pH (6-7), neutral loam in the range of 0-20 cm on the surface of the soil, bulk density 1.29g/cm3, and the ratio of total porosity to solid phase 1∶ 1. This kind of soil has suitable elasticity, not only good air permeability and drainage, but also good water retention. 20 ~ 40 cm soil layer is heavy loam, with physical sand and physical clay accounting for about half, soil bulk density 1.32 g/cm3, total soil porosity of 50%, including air porosity of 7%. The soil is slightly dense, but it has strong water and fertilizer retention ability, which can prevent water and nutrient leakage. This kind of soil is characterized by moderate viscosity, high organic matter content, softness and air permeability, which is beneficial to seedling growth and root development; The lower soil is rich in nutrients, which can keep water and fertilizer, and provide sufficient nutrients for the rhizome expansion of ginger in the later growth stage, which is very suitable for cultivating ginger with high yield and good quality. Gushan Village in Laiwu City is a concentrated ginger producing area, with undulating hills, loose soil, suitable pH and good irrigation and drainage conditions, which is also very suitable for planting ginger (Table 4).

Table 4 Physical properties of soil in main ginger producing areas

From the perspective of soil fertility, the organic matter content is relatively high, and the organic matter content in plain production areas is generally above 1.5%, and the highest is 2.96%. Available nitrogen and potassium are rich, especially available potassium, which is closely related to the high yield and high quality of ginger (Table 5). As can be seen from Table 5, there are some differences in soil fertility between plain producing areas and hilly producing areas. The soil fertility in plain ginger region is good, and the contents of organic matter and available nitrogen, phosphorus and potassium are obviously higher than those in hilly ginger region.

Table 5 Soil Fertility in Main Ginger Producing Areas

Note: The sampling plot 1, 2, 3 are plains and 4 are hills.

Although ginger does not require high soil texture, different soil textures have certain effects on the yield and quality of ginger (Table 6). Sandy soil generally has good air permeability, the ground temperature rises rapidly in spring, and the seedlings grow rapidly, but the organic matter content is often low, and the water and fertilizer conservation performance is slightly poor. If the top dressing of ginger is not timely in the late growth stage, it is easy to reduce production due to fertilizer removal. In spring, the temperature of clayey soil rises slowly, so the growth of seedlings is also slow, but it is rich in organic matter, with strong water and fertilizer conservation ability and lasting fertilizer effect. In the late growth stage of ginger, it can still provide sufficient nutrients for rhizome expansion, so the yield is high.

Table 6 Effects of Different Soil Quality on Ginger Quality

(2) Requirements for soil pH value

Ginger at seedling stage, especially at seedling stage, has wide adaptability to soil pH and is not very sensitive to reaction. According to Zhang Shulan's experiment, the growth of ginger seedlings planted in soil with pH value of 4 ~ 9 is basically normal, and there is no obvious difference in performance. From the middle and late July, that is, the late stage of seedling growth, it can be seen that different pH values have obvious effects on plant growth, especially after entering the vigorous growth period.

① Effect of soil pH value on the growth of ginger stems and leaves. According to the investigation on the growth status of plants under different treatments in September 1 1 year and October 23rd1year, the results showed that (Table 7) the plants with 7)pH 7 were the highest, which were 80 cm and 83.2cm； respectively. Followed by plants with pH values of 5 and 6, plants with pH values of 4 and 8 and 9 are shorter. 10 year123 October, the plant height with pH value of 8 and 4 was only 62 cm and 67 cm respectively. Especially in the treatment of pH 9, the plant is the shortest, and the plant height at harvest is only 53.8 cm. The results showed that the height of the above-ground stems of ginger was basically normal in the range of soil pH value from 5 to 7, but when the soil pH value was lower than 4 or higher than 8, the growth of ginger was obviously inhibited.

Soil pH value not only affects the height of the above-ground stem of ginger, but also has obvious influence on the occurrence and growth of leaves. Taking the harvest survey of 65438123 October as an example, when the pH is 7, each plant has an average of 169.4 leaves. When pH is 5 and 6, the number of leaves is slightly less than the former. When treated with pH 9, the number of leaves per plant was only 55.4, which was only about 65,438+0/3 of the former, and the plant was short and weak. It can be seen that too strong acidity or alkalinity is unfavorable to the growth of Jiang Ye. In the range of pH 5 ~ 7, it is suitable for the occurrence and growth of Jiang Ye.

Table 7 Effects of soil pH on plant height and leaf growth of ginger

Table 7 Effects of Soil pH on Plant Height and Leaf Growth of Ginger (Continued)-1

② Effect of soil pH value on the growth of branches and rhizomes. The number of branches of ginger is closely related to the yield of rhizome. According to the experiment (Table 8), ginger grows vigorously and has many branches under neutral and slightly acidic conditions. For example, when the pH is 5 ~ 7, taking the investigation of 65438+1October 23rd as an example, each plant has 12 ~ 14.8 branches on average; There are few branches under acidic conditions, such as 10.2 branches per plant at pH 4; Under alkaline or strongly alkaline conditions, the number of branches is even less. For example, when pH is 8 and 9, the average number of branches per plant is only 5.6 and 5.4 respectively. The difference between the treatments is very significant. It can be seen that alkalinity, especially strong alkalinity, will seriously inhibit the occurrence and growth of ginger branches, thus affecting the yield of rhizomes.

Table 8 Effect of pH on Branching and Rhizome Growth of Ginger

Table 8 Effect of pH on the Growth of Branches and Roots of Ginger (Continued)-1

It can also be seen from Table 8 that ginger is not alkali-tolerant. When pH is higher than 8, not only the growth of stems and leaves is inhibited, but also the development of rhizomes is poor. On average, there are only 10 ginger balls per plant, and the average root weight per plant is only104 ~17 grams, and the ginger slices are thin and small. When the pH is 5 ~ 7, the rhizome is large and well developed, with an average of more than 20 ginger balls per plant, and the weight of each rhizome is about three times that of the former. Among them, the treatment of pH 6 has the best rhizome growth, with 25.6 ginger balls per plant and a fresh weight of 362 grams per plant.

To sum up, the strength of soil pH has a significant effect on the growth of ginger aboveground stems and leaves or underground rhizomes. Ginger likes neutral and slightly acidic reaction, is not resistant to strong acid and alkali, and has strong adaptability to soil pH. According to the experimental results, plants grow well in the range of pH 5 ~ 7, and rhizomes grow best at pH 6. When pH is above 8, it has obvious inhibitory effect on the growth of ginger organs, which is characterized by short plants, yellowing leaves, poor growth and poor rhizome development. The production practice also shows that ginger cultivated in saline-alkali land is not only short in plants, but also slender in stems, few in branches, thin and sparse in leaves, thin in rhizomes and low in yield. Therefore, we should pay attention to soil selection when planting ginger, and it is not suitable to plant ginger in saline-alkali waterlogged depression. If you want to plant ginger in alkaline soil, you need to improve the soil and adjust the pH of the soil to a range suitable for ginger growth, so that ginger seedlings can grow well.