Soil restoration lecture 4- Marc Flashcards
what does REDD + stand for
REDD+ Reducing Emissions from Deforestation and Forest Degradation
what does the + signify in REDD +
+ Conservation of forests
+ Sustainable management of forests
+ Enhancement of forest carbon stocks
what is the main aim of REDD+?
biomass sink enhancement
how is REDD + achieved?
Stop deforestation 1.1 GtC/y
Remove CO2 by restoring forest capacity over next 50 years at average rates that
Allow current second growth forests to reach maturity 2 GtC/y
Restore degraded forests 1 GtC/y
Reforest recently deforested lands 1 GtC/y
what is the 4 per mille initiative?
A growing international coalition of nation-states, international organizations, NGOs, research centers, universities, farmers organizations, and businesses
The ‘4 per mille’ initiative, launched at the Paris Climate Conference in 2015, proposed that current annual CO2 emissions from fossil fuel burning could be completely offset if the global stock of soil organic carbon (SOC) was increased annually at the rate of 4 parts per 1000 (4‰ or 0.4%) of the current value.
give examples of practices that will increase soil organic carbon
Conservation tillage, residue management and mulch farming
Apply organic wastes to soil
Use N and other nutrient sources more efficiently
Convert marginal and degraded lands to restorative land uses
Eliminate summer (bare) fallow and incorporate legumes and other appropriate cover crops in rotations
Agroforestry
what does regeneratig soils have the potential to do?
to mitigate climate change and improvefood security
What is the most effective way of regenerating soil?
Restore soils to sequester carbon back where it belongs, in the soils and in the plants: this is the most efficient and safest climate mitigation strategy
is soil regeneration feasible? Via carbon sequestration
it depends on how much C is already there, may be at it’s peak so sequestration wont be able to add much more. Depends how long improved management has been practiced on the site
what other elements should be considered in regeneration ( not Carbon Dioxide)
CH4 + N2O
give examples of how chemicals may be locked in during rice growth
in rice growth…. incoroporate rice straw to improve plant growth + slow decomposition.
but high CH4 emissions from rice fields
what is biochar?
Biochar is the product of pyrolysis of biomass
Heating of biomass in low oxygen environments
how does biochar work?
Carbon captured by photosynthesis (biomass) from the atmosphere is locked into the biochar, preventing degradation and return of carbon into the air. Biochar is then applied into the soil.
what is the modern production procedure of biochar?
Pyrolysis: thermal decomposition in the absence of oxygen
Products from pyrolysis: gas, bio-oil and a solid char
Gasification: conversion of biomass into carbon monoxide, carbon dioxide, hydrogen, methane and nitrogen with a limited supply of oxygen and/steam
Products from gasification: syngas (mixture of gases CO, CH4, H2) and char
how long does biochar take to degrade? is it stable?
Biochar is very stable in soil and degraded over centuries/millennia
benefits and risks of biochar amendment?
improves crop productivity mainly by increasing nutrient use efficiency and water holding capacity.
improvements to crop production are often recorded in highly degraded and nutrient-poor soils: application to fertile and healthy soils does not always increase crop yield.
what is bioremediation
the use of either naturally occurring or deliberately introduced microorganisms to consume and break down environmental pollutants, in order to clean a polluted site.
what is lignin?
a plant polymer in soil
what can lignin be used for?
biostimulation
what is biostimulation?
involves the modification of the environment to stimulate existing bacteria capable of bioremediation.
what does PAH stand for?
polycyclic aromatic hydrocarbons
whats the aim of phytoremediation
Can enhance PAH dissipation from soil by plant uptake (phytoextraction), or stimulating microbe activity through root exudates (rhizoremediation)
what is a Rhamnolipid
Rhamnolipid– a biosurfactantproduced by Pseudomonas aeruginosa
what do surfactants do?
increase water solubility of hydrophobic organic pollutants
Enhances plant uptake and microbial degradation
whats the difference between Biosurfactants and artificial surfactants
Biosurfactants are less toxic than artificial surfactants, and are biodegradable
T/F A variety of complex factors determine soil fertility
T
soil degredation is only caused by one source T/F
Various practices lead to soil degradation, which could begin to limit food production globally
What happens to waterlogged soils?
Waterlogged soils become anoxic, which slows respiration but leads to CH4 formation
what does the REDD+ and 4 per millle initiative try to achieve?
restore and protect forests/soils
what can dramatically influence soil health?
Land management practice can dramatically influence soil health
how can soils be directly intervented?
bioremdiation
