بوم شناسی کشاورزی (Mar 2025)
The Effect of Animal Manure and Humic Acid on Some Physiological Traits of Cotton (Gossypium hirsutum L.) Under Irrigation Water Salinity Conditions
Abstract
Introduction Salinity stress is an important abiotic stress threatening the production of cotton in arid and semi-arid regions of the country and the world, which can be reduced by the proper use of organic materials. Cotton is the most important fiber product, which is widely cultivated for agricultural and industrial purposes in temperate and hot regions of more than 15 countries of the world. Although cotton is known as a salinity-tolerant plant, not only is the resistance to salinity limited in this plant, but different stages of development also show different reactions to salinity. One of the effects of stress is disturbing the nutritional balance in the plant. Proper nutrition during times of stress can partially help the plant deal with various environmental stresses. In this regard, by using fertilizers containing micronutrient elements, firstly, plant yield increases, secondly, increasing the concentration of these elements in agricultural products plays an important role in improving the quality of food consumption. Using organic fertilizers, especially organic and animal manure such as humic acid, can improve the performance and performance components of different products under stress conditions. Materials and Methods To study the effect of manure and humic acid on some of the physiological qualities of cotton under salt water salinity stress, an experiment was conducted as factorial split plots (factorial split plot) in which different levels of irrigation water salinity at three levels (2.5, 5.5 and 8.5 ds.m-1) as the main factor and two treatments of manure at two levels (0 and 20 t/h) and humic acid at two levels (0 and 200 gr/100 kg of seeds) as sub-factor in 4 replications in a farm located in Boshrouyeh city in 1398 years. The software SAS (V9.1) and Excel were used to analyze the data and draw the figures. Means were compared using the FLSD test at a 5% probability level. Results and Discussion Analysis of variance results showed that the simple effects of three experimental factors (salinity stress, manure, and humic acid) were significant on all studied traits (on the relative water content, Electrical conductivity and membrane stability, chlorophyll a and b contents, and proline content). With increasing salinity level, increased proline content (286.5%), membrane Electrical conductivity (4.2%) and carotenoids (88.79%) and decreased chlorophyll a (20.7 1 %) and b content (39.38%), relative water content (23.16%) and membrane stability (13.54%). The application of animal manure and humic acid increased the relative water content, membrane stability and chlorophyll content under stress conditions, which indicates the modifying effect of these fertilizers in reducing the adverse effects of salinity stress. The interaction effects were significant, too. Conclusion The results of this research showed that the use of water with high salinity, such as salinity of 8 ds.m-1, caused significant changes in the physiological traits of the plant, including relative leaf water content, membrane stability, membrane electrolyte leakage, chlorophylls, and proline. With increasing salinity levels, the amount of proline, membrane electrolyte leakage, and carotenoid increased, and the content of chlorophyll a and b, relative water content, and membrane stability decreased. The application of animal manure and humic acid increased the relative water content, membrane stability, and chlorophyll content under stress conditions, which indicates the moderating effect of these fertilizers in reducing the adverse effects of salinity stress. Considering the positive effects of using organic fertilizers in this experiment, it is recommended to test and investigate the use of humic acid during the growing season in addition to the use of animal manure before planting and the use of humic acid in bulk Thus, it is suggested to use humic acid and animal manure in cotton cultivation to adjust the salinity levels.
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