This book addresses basic and applied aspects of two nexus points of microorganisms in agro-ecosystems, namely their functional role as bio-fertilizers and bio-pesticides. Readers will find detailed information on all of the aspects that are required to make a microbe “agriculturally beneficial.” A healthy, balanced soil ecosystem provides a habitat for crops to grow without the need for interventions such as agro-chemicals. No organism in an agro-ecosystem can flourish individually, which is why research on the interaction of microorganisms with higher forms of life has increasingly gained momentum in the last 10-15 years. In fact, most of plants’ life processes only become possible through interactions with microorganisms. Using these “little helpers” as a biological alternative to agro-chemicals is a highly contemporary field of research. The information presented here is based on the authors’ extensive experience in the subject area, gathered in the course of their careers in the field of agricultural microbiology. The book offers a valuable resource for all readers who are actively involved in research on agriculturally beneficial microorganisms. In addition, it will help prepare readers for the future challenges that climate change will pose for agriculture and will help to bridge the current gaps between different scientific communities.

This report presents the world nitrogen, phosphorus and potassium fertilizer medium-term supply and demand forecasts for the period 2017-2022. FAO, in collaboration with other members of the Fertilizer Outlook Expert Group dealing with fertilizer production, consumption and trade, provides forecasts of world and regional fertilizer supply, demand and potential balance.

Approximately one-third of all food produced globally goes to waste, promoting a growing demand to recycle and recover wasted nutrients using sustainable waste management technologies such as composting and anaerobic digestion. Organic end-products from composting and anaerobic digestion have low nutrient contents making agricultural utilisation challenging (economically and practically) relative to synthetic fertilisers. However, organic end-products can enhance physical and biological properties of soil that can have syngeneic effects when combined with synthetic N. This study investigated synergistic relationships between food waste-derived organic soil applied at a rate of 50 kg ha-1 total N [compost or anaerobic digestion effluent (liquid digestate (LD) or solid digestate (SD))] and two rates (50 and 100 kg ha-1 total N) of synthetic N [urea ammonium nitrate (UAN)] to produce sustainable waste-derived fertiliser products. Greenhouse gases (CO2, N2O), soil chemistry (NH4+-N, NO3-N, pH) and microbial biomass C (MBC) during 56 days of soil incubation were quantified. The application of organic soil amendments produced lower N2O emissions than UAN. LD + UAN 50 decreased cumulative N2O emissions by 23% compared to the UAN 100 despite having the same total N (100 kg ha-1) and the same available N rate. Therefore, replacing UAN for LD in farming practices has the potential to not only supply an equivalent amount of available N in the soil, but also lower N2O emissions. SD produced the highest CO2 emissions, followed by LD and compost. SD +UAN 50 increased MBC levels due to the high levels of carbon and increased labile carbon and available nitrogen due to the application of UAN. The major drawback of using SD compared to LD is that the evaporation of LD caused high ammonia volatilisation rates, reducing available N in SD. Therefore, future studies should explore strategies to reduce ammonia volatilisation of LD.

Nitrogen is one of the most critical elements for all life forms. In agricultural systems it is essential for the production of crops for feed, food, and fiber. The ever-increasing world population requires increasing use of nitrogen in agriculture to supply human needs for dietary protein. Worldwide demand for nitrogen will increase as a direct response to increasing population. Nitrogen in the Environment provides a wholistic perspective and comprehensive treatment of nitrogen. The scope of this book is diverse covering a range of topics and issues related to furthering our understanding of nitrogen in the environment at farm and national levels. Issues of nitrogen from its effects on crops and human nutrition to nitrogen in ground water, watersheds, streams, rivers, and coastal marine environments are discussed to provide a broad view of the problem and support scientists, researchers, and engineers in formulating comprehensive solutions. - The only source which presents an international, wholistic perspective of the effects of nitrogen in the environment with worldwide mitigation practices - Provides details on how to improve the quality of the environment by analyzing the development of emerging technologies - Develops strategies to be used by soil scientists, agronomists, hydrologists, and geophysicists for broad scale improvement of nitrogen efficiency