Soil Chemical Analysis

Introduction to Soil Microbiology

External agricultural inputs such as mineral fertilisers, organic amendments, microbial inoculants, and pesticides are applied with the ultimate goal of maximising productivity and economic returns, while side effects on soil organisms are often neglected. We have summarised the current understanding of how agricultural inputs affect the amounts, activity, and diversity of soil organisms. Mineral fertilisers have limited direct effects, but their application can enhance soil biological activity via increases in system productivity, crop residue return, and soil organic matter. Another important indirect effect especially of N fertilisation is soil acidification, with considerable negative effects on soil organisms. Organic amendments such as manure, compost, biosolids, and humic substances provide a direct source of C for soil organisms as well as an indirect C source via increased plant growth and plant residue returns. Non-target effects of microbial inoculants appear to be small and transient. Among the pesticides, few significant effects of herbicides on soil organisms have been documented, whereas negative effects of insecticides and fungicides are more common. Copper fungicides are among the most toxic and most persistent fungicides, and their application warrants strict regulation. Quality control of organic waste products such as municipal composts and biosolids is likewise mandatory to avoid accumulation of elements that are toxic to soil organisms.

Impact of agricultural inputs on soil organisms—a review

Plant nutrients are essential for production of crop and healthy food for the word's expanding population. Plant nutrients are therefore a vital component of sustainable agriculture. Increased crop production largely relics on the type of fertilizers used to supplement essential nutrients for plants. The nature and the characteristics of nutrients release of chemical, organic and biofertilizers are different, and each type of fertilizer has its advantages and disadvantages for crop growth and soil fertility. A sound management of fertilization must attempt to ensure both enhanced and safeguard the environment; therefore, a balanced fertilization strategy that combines use of chemical, organic and /or biofertilizers must to be developed and evaluated.

The Combined Use of Chemical, Organic Fertilizers and/or Biofertilizer for Crop Growth and Soil Fertility

The World Health Organization (WHO) states that in developing nations, there are three million cases of agrochemical poisoning. The prolonged intensive and indiscriminate use of agrochemicals adversely affected the soil biodiversity, agricultural sustainability, and food safety, bringing in long-term harmful effects on nutritional security, human and animal health. Most of the agrochemicals negatively affect soil microbial functions and biochemical processes. The alteration in diversity and composition of the beneficial microbial community can be unfavorable to plant growth and development either by reducing nutrient availability or by increasing disease incidence. Currently, there is a need for qualitative, innovative, and demand-driven research in soil science, especially in developing countries for facilitating of high-quality eco-friendly research by creating a conducive and trustworthy work atmosphere, thereby rewarding productivity and merits. Hence, we reviewed (1) the impact of various agrochemicals on the soil microbial diversity and environment; (2) the importance of smallholder farmers for sustainable crop protection and enhancement solutions, and (3) management strategies that serve the scientific community, policymakers, and land managers in integrating soil enhancement and sustainability practices in smallholder farming households. The current review provides an improved understanding of agricultural soil management for food and nutritional security.

Impact of Agrochemicals on Soil Microbiota and Management: A Review

Illicit drugs and the environment--a review.

Effect of arsenic contamination on microbial biomass and its activities in arsenic contaminated soils of Gangetic West Bengal, India

The pollution status of atmospheric carbonyls in a highly industrialized area.

Investigation of carbonyl compounds in air from various industrial emission sources.

Clay loam soil from agricultural field of Gangetic alluvial zone of West Bengal was investigated to evaluate the effect of chlorpyrifos application at field rate (0.5 mg kg(-1) soil) and 100 times of the field rate (50 mg kg(-1) soil) on soil microbial variables under laboratory conditions. Acetone-induced stress on soil microorganisms was evident in the initial stages in terms of microbial biomass carbon (MBC) content in soil and basal soil respiration (BSR) in control soil samples which received acetone only as compared to control soil without acetone. The soil MBC content increased significantly by application of chlorpyrifos. The BSR and the fluorescein diacetate hydrolysing activity (FDHA) were not adversely affected by chlorpyrifos at field rate, whilst the chemical at higher dosage significantly decreased the metabolic activities of soil microbes in terms of BSR and FDHA.

Raktim Pal

Papers

Illicit drugs and the environment--a review.

Effect of arsenic contamination on microbial biomass and its activities in arsenic contaminated soils of Gangetic West Bengal, India

The pollution status of atmospheric carbonyls in a highly industrialized area.

Investigation of carbonyl compounds in air from various industrial emission sources.

Effect of chlorpyrifos on microbial biomass and activities in tropical clay loam soil.