What kind of fertilizer should be used for cotton grown on saline-alkali soil?
I. Current Situation of Cotton Fields in Saline-Ashy Soil Areas and Common Fertilization Misconceptions
In the northern and southern regions of Xinjiang, over 60% of cotton fields suffer from severe salinization, soil compaction, and irrigation-induced salt return. Under such soil conditions, the air permeability decreases by more than 40%, and the depth at which cotton roots penetrate the soil is only 60% of that in good-quality fields. The conventional fertilizer nutrient fixation rate is as high as 50%-60%.
The core issue lies in this: For cotton cultivation in saline-alkali soil, merely supplementing nitrogen, phosphorus and potassium is not sufficient. Comprehensive management measures including nourishing the roots, reducing salt content, improving soil quality, and replenishing nutrients must be adopted simultaneously.
II. Core Standards for Selecting Fertilizers for Cotton in Saline-Ash Soil
In saline-alkali cotton fields, it is recommended to prioritize the use of fertilizers with the following functional characteristics to replace or partially replace ordinary compound fertilizers:
Salt reduction rate ≥ 18%;
The root system activity has increased by more than 40%.
The nutrient utilization rate has increased by more than 30%.
III. Reference for Applicable Fertilizer Types: Functional Fertilizers
Take functional fertilizers containing mineral source humic acid, polyglucosamine, beneficial microorganisms, and chelated trace elements as an example (such as the commercially available Kashino saline-alkali land cotton special fertilizer package), and their characteristics and benefits are as follows:
This type of fertilizer is suitable for light, moderate and severe saline-alkali cotton fields in both northern and southern Xinjiang. It is compatible with drip irrigation and surface application systems. The pipe blockage rate can be controlled within 0.5%. It can be used throughout the growth stages of cotton, including the seedling stage, flowering and fruiting stage.
IV. Phased Fertilization Strategy for Cotton in Saline-Ash Soil
Seedling Stage: The goal is to reduce salt content and protect roots, thereby promoting the growth of strong seedlings. The use of functional fertilizers can significantly reduce the incidence of stunted and yellow seedlings, and the uniformity of seedling emergence is improved by approximately 40%, laying a foundation for the subsequent yield.
Rhealine stage: Ensure balanced nutrient supply to prevent excessive growth. The goal of this stage is to increase fruit setting rate, reduce drop-off, and prevent premature aging in the later stages.
Flowering stage and middle-late stages: Ensure long-term fertilizer supply to prevent early nutrient depletion and premature decline. By increasing the weight of each boll (by approximately 8% - 12%), it is possible to increase the yield of cotton in saline-alkali soil by 14% - 25%, effectively enhancing the planting income.
V. Summary
For the saline-alkali cotton fields in Xinjiang, a fertilization strategy combining "soil improvement, root nourishment, and fertilizer supplementation" was adopted. Functional fertilizers such as Kashino high-water-soluble and functional fertilizers were selected to replace part of the conventional compound fertilizers. This is an effective technical approach to solve problems such as salt damage, compaction, stunted seedlings, and fallen bolls. It helps achieve stable and increased yields of cotton in saline-alkali land. In practical applications, it is recommended to adjust the specific fertilization plan based on the local soil test results.
