Chapter 4 Soil, Fertilizer, and Water 
Management of Grapes 
Soil is the basis for grape growing and fruiting. The structure and physicochemical characteristics of the soil provide and coordinate the necessary moisture and nutritional conditions for grape growth and development, and they are closely related to grape growth and development. Soil conditions largely determine the nature, plant life, fruit yield, and quality of grape cultivation, as well as the quality and flavor of wine. Soil management is an important work in the vineyard, 
and good soil management is the prerequisite for the healthy production of grapes and the basis for environmental protection and sustainable development. 
I. Soil Properties in the Vineyard 
As for orchards, the basic properties of the soil shall mainly include water and fertilizer retention capacity, related soil structure, soil porosity, and soil acidity_x0002_alkalinity. If conditions are met, the orchard soil management will adopt sod culture or various covering methods. Therefore, the soil tilth in orchards is not as important as in farmlands planted with food crops and cash crops like vegetables. 
(I) Soil Porosity 
Soil aggregate and soil particle (single particle) are mutually supported in the soil to form various tortuous pores with uneven thickness and different shapes, which can be classified into inactive pores, capillary pores, and ventilation pores. Pores between solid soil aggregates and between soil particles are the places where moisture and air exist and circulate. The soil must have sufficient pore volume and appropriate proportion and distribution of large and small pores, to facilitate the 
fertile and water supply and the normal growth and development of the root systemof crops. Porosity is the general term for pore volume (generally expressed in the degree of porosity), proportion and distribution of large and small pores. The proportion of pores of different sizes in the soil is of great significance in agricultural production. Generally, due to artificial measures such as frequent cultivation, irrigation, and fertilization, most soil particles are loosely arranged in 
the plow layer, with a good aggregate structure. The soil is loose generally with a porosity above 50% and low bulk density. The soil layer below the plow layer is the opposite. Too loose soil has weak cohesion between soil particles, and large pores are dominant. Although it is easy to cultivate, too loose soil also makes it difficult for the plant to take root, and it has a poor water-retaining capacity, is prone to air leakage and soil moisture loss and soil nutrient loss with precipitation or irrigation. Too compact soil has a large number of small pores, which leads to poor aeration and water permeability. It is easy to produce excess surface water or surface runoff. 
Lack of air in soil affects microbial activity and nutrient transformation. Besides, it also affects the cultivation quality, the emergence of seedlings, and the normal development of the plant root system. Sandy soil particles are coarse, with small porosity and large pore size, which is conducive to water permeability and aeration, but its water retention capacity is poor. Clay, on the contrary, has large porosity, but it has many invalid pores. Although its water retention capacity is strong, its water permeability and aeration are poor, and the clay temperature is not easy to rise. 
Loam lies between sandy soil and clay, with proper porosity, which has good water permeability and good water retention capacity. 
(II) Structure of Soil 
In any kind of soil, except for pure sand, all levels of soil particles agglomerate with each other for different reasons into soil aggregates, clods, and patches with different sizes, shapes, and properties, which are referred to as soil structures. The existence and arrangement of these structures with different forms in the soil will change the porosity of the soil and directly affect the soil fertility, nutrient movement, and change of tilth. Generally speaking, the coarser the soil texture is, the larger the bulk density is, and the smaller the total porosity of the soil is. The 
finer the texture of the soil is, the smaller the bulk density is, and the greater the total porosity of the soil is. The suitable porosity is as follows: the total porosity of plow layer soil (0–15 cm) is 50%–60%, and the aeration porosity is 15%–20%, and those of basement soil (15–30 cm) are 50% and 10% respectively. A complete set of measures of autumn plowing can loosen the soil and form soil aggregates of suitable size, improve the soil structure, reduce the soil bulk density, and increase the porosity. The higher the content of soil organic matter is, the more obvious the 
improvement of clay soil porosity is. 


The best soil structure for farming is an aggregate structure with a particle size of 2–3 mm. Soil with aggregate structure has strong stability and good porosity that balance water permeability and water retention. There are a large number of various microorganisms in the soil, which is conducive to the decomposition of organic matter and the release of nutrients. The soil with aggregate structure has a moderate proportion of solid, liquid, and gas phases, which also brings good thermal conditions and is conducive to crop growth and development. The total porosity of block, core, column, prism, and sheet structures is small, and the pores are mainly small inactive pores and capillary pores. Large aeration pores between structures often become channels of water and fertilizer leakage. The root system of plants is difficult to penetrate such structures and is often torn off in case of crack, so they are referred to as bad structures. The aggregate structure not only has a large total porosity but also has a large number of multi-level large and small pores in its interior. The arrangement between aggregates is loose, and there are many large pores, which have the dual functions of water storage and aeration, so it is referred to as a good structure. 
The high content of organic matter in soil is the decisive condition for the formation of soil aggregate structure. Compared with farmland, it is easier to implement soil management methods for orchards, such as green manure crop planting, sod culture, and straw mulching, which is conducive to the formation of soil aggregate structure. It is necessary to irrigate rationally and till at the right time. Irrigation by flooding could easily destroy the soil structure and make the soil 
harden. After irrigation, it is necessary to intertill and loosen the soil at the right time to prevent hardening. Frequent irrigation by flooding, frequent intertilling and weeding, and irrational application of chemical fertilizers in orchards are not conducive to the formation and stability of soil aggregate structure. Tilling at the right time and giving full play to the roles of alternation of wetting and drying and alternation of freezing and thawing are conducive to the formation of a large number of water-unstable aggregates and the regulation of soil structure. Lime and gypsum can be applied. Application of lime in acidic soil and gypsum in alkaline soil not only can reduce the acidity or alkalinity of soil but also can help form soil aggregates. Application of soil structure conditioner: According to the principle of aggregate structure formation, humic acid, cellulose, lignin, etc. are extracted from plant residues, peat, lignite, and other raw materials. At present, tests have been conducted on the sodium salt of hydrolyzed polyacrylonitrile or the calcium salt of the copolymer of vinyl acetate and maleic acid. In recent years, humic acid fertilizer has been widely used in China. In many areas, locally produced lignite and peat can be used to produce humic acid fertilizer. It is a solid gel and can play a good role in structural improvement. 
(III) Soil Tilth 
Soil tilth refers to the characteristics of soil during cultivation, which is a comprehensive reflection of a series of physical properties and physicalmechanical properties of the soil. The tilth closely affects soil tillage quality and fertility. 
Generally, the tilth can be summarized into three aspects: ① Difficulty of tillage. Farmers regard the difficulty of tillage as the primary condition to determine the soil tillage quality. Any soil that is labor-saving and easy to till is referred to as “l(fā)ight”, “l(fā)oose” and “soft” soil by the masses; any soil that is labor-consuming and hard to till is referred to as “heavy”, “tight” and “stiff” 
soil by the masses. It is difficult to till the soil with low organic matter content and poor structure. The difficulty of tillage directly affects the efficiency of soil tillage. ② Tillage quality. The tillage quality of the soil is different. Any soil that is loose after tillage, easy to rake and break, has moderate porosity and is conducive to the germination of seeds and the growth of seedlings will be deemed to have a good tillage quality; otherwise, it will be deemed to have a bad tillage quality. ③ Length of suitable tillage period. For soils with a good tilth, it is suitable for a long tillage time, 
which is characterized by “it is easy to till if it is dry or wet and even easier to till if it is moderately dry or wet”. 


However, for soils with a bad tilth, the suitable tillage period is short, generally only 1–2 days. If the suitable tillage period is missed, it is not only difficult to till but also labor-consuming, and the tillage quality is poor, which is characterized by “being soft in the morning, hard at noon, and stiff in the afternoon”, and this kind of soil is referred to as “hour soil” by the masses. The length of a suitable tillage period is closely related to soil texture and soil water content. The suitable tillage period of sandy loam soil and sandy soil is long, while that of clayey soil is short. In production practice, attention should be paid to soil tillage and improvement of soil tilth. ① Prevention of pressing soil. The tightening of the tilled soil under the action of rainfall, irrigation, trampling by people and livestock, and agricultural machinery is referred to as the soil pressing process. With the development of agricultural mechanization, the number of large machines and tools is increasing gradually, and the problem of soil pressing will become more prominent in the future. 


To prevent soil pressing, firstly, it is required to improve the tillage quality; secondly, unnecessary operations should be reduced as much as possible or joint operation should be adopted to alleviate the soil pressing and reduce the production cost; thirdly, the no-tillage or less tillage method may be adopted to reduce the mechanical pressing and keep the soil loose. ② Attention should be paid to the suitable tillage state and period of the soil. Farmers in all parts of China have rich experience in grasping the suitable tillage state and the suitable tillage period of soil. For example, you can take a handful of soil, hold it tightly, and then let go of the hand. If it is loose, it is suitable for tillage. Or you can hold the soil into a soil aggregate, then let go of the hand to make the soil aggregate fall to the ground, if it is scattered, then it is suitable for tillage.