Quantifying the Impact of Organic Fertilizers on Soil Quality under Varied Irrigation Water Sources

Abstract

The issues of limited water availability and excessive fertilizer utilization, both of which negatively impact soil health and crop productivity, are key focal points in the pursuit of sustainable agricultural progress. Given these crucial obstacles, it is crucial to utilize accurate methods of irrigation and fertilization in order to improve the condition of the soil and promote the progress of sustainable farming. The objective of this research is to determine the optimal indicators for creating a minimal data set (MDS) that can assess the influence of organic fertilizers on the quality of pakchoi soil in varying irrigation water sources. Principal component analysis and norm values were utilized to create the MDS, and its accuracy was confirmed by examining coefficients of Nash efficiency and relative deviation. The results of our study showed that there was not much difference in soil bulk density (BD), but there was moderate variation in soil water content (SWC), soil salt content (SSC), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), available potassium (AK), and organic matter (OM). The selected MDS indicators included BD, AN, and OM. The soil quality index (SQI) achieved a high R2 value of 0.952, indicating a strong correlation. Furthermore, the nonlinear evaluation model showed a high level of effectiveness and efficiency, with Ef and Er values of 0.899 and 0.046, respectively. The effectiveness of this model in evaluating soil quality under different irrigation water conditions is evident. Notably, treatments involving magnetized–ionized brackish water (average SQI = 0.524) and the application of 20 kg/ha organic fertilizer (average SQI = 0.719) demonstrate the capacity to enhance soil quality. The present study presents a pragmatic, productive, and economical quantitative evaluation approach that can be used for worldwide vegetable farming with the utilization of clean water, saline water, magnetized–ionized saline water, and organic manure. Thus, we encourage vegetable growers to consider adopting both magnetized–ionized brackish water and organic fertilizers, and the utilization of the nonlinear soil quality index evaluation model is recommended as it offers a sensitive and effective approach to assessing soil quality across various irrigation and organic fertilizer schemes.