soil nutrient supplies and fertalizer Flashcards
what for dd plants take up nutrients. ionic or covalent
ionic
is there enough nutrients in the soil
nutrient levels in the soil at any moment in time are much less than what is required over the growing season. therefore the soil solution must be replenished with nutrients
how are nutrients replenished in soil solution
soil reserves (internal source) fertilizers (external sources)
for internal sources how can nutrients be replenished
they can be transformed from organic to inorganic form through mineralization
dissolution, (imporant for P)
desorption
what is colloid
organic and inorganic matter with very small particle sizes and correspondingly large surfaces are per unit of mass. ex.. clay, SOM
why is there a need for nutrient management
if the supply of nutrient are adequate, the crop will remove the characteristic amount of nutrients from the soil
removal of nutrients from the soil cant continue indefinitely without depleting the production of the soil
if supplies of any nutrients are insufficient, growth and subsequently yields will suffer
what are fertilizers
natural or artificial substances that contain nutrient elements that improve plant growth and productivity. fertilizers enhance the natural fertility of the soil and replace elements removed from the soil by previous crops
what are organic fertilizers
derived from living matter and contain carbon (e.g. compost, manure, sewage sludge)
what are inorganic fertilizers
synthetic or mined and processed fertilizers. macro and micronutrients are available
how are nitrogen fertilizers made
manufactured using natural gas and element N2 under high temperature and pressure to synthesize ammonia gas NH3
how are phosphorous fertilizers made
processed by dissolving phosphate rocks with sulfuric acid
how are potassium fertilizers made
simply purified from natural geological deposits of salts formed from the evaporation of ancient seawater
what is the fertilizer regulation
fertilizers are defined by the fertilizer act of the government of Canada and there sale is regulated by the Canadian food inspection agency (CFIA)
what is the definition according to the fertilizer act
“any substances or mixture of substances, containing N, P, K or other plant food, manufactures, sold or represented for use as a plant nutrient”
how is the analysis of chemical fertilizers legislated and expressed in numbers according to the content of
total N, available phosphoric acid P2O5, and soluble potash K2O also known and the fertilizer grade
is there is a fourth number in the fertilizer grade what does it represent
if would represent Sulphur
what it the issue with P and K in the fertilizer grade
P2O5 and K2O are given as a method of expression old. there is no P2O5 and K2O in fertilizers. this means that to get the actual amount of P and K we have to convert from oxide to element form
what happens if we add too much fertilizer
we can see toxicities this means that there is a ideal amount
what is the order of the fertilizer grade
N-P-K-S
what are the fertilizers fate
plants take up nutrients from the soil as well as the fertilizers, fertilizers supplement what the soil can provide
plants don’t utilize 100% of the nutrients added in fertilizers
nutrients from fertilizers also interact with soil and are subject to the multitude of processes involved in nutrient cycling
therefore understanding nutrient cycling is critical to managing nutrients and fertilizers to use to avoid economic impact and environmental harm
what are the four R for nutrient management
right source, right rate, right time, right place.
matches fertilizers crop need matches the amount of fertilizers to crop needs, matches nutrient supply when crops need them, keep nutrients in the soil where the crop can use them
what is the goal of the 4R’s
to match nutrient supply with crop requirements to minimize nutrient losses from the fields
what is the 4R nutrient management
it involves the implementation of the best management practices (BMPs) that optimizes the efficient use of fertilizers
BMPs will be location-specific because they depend on soil and climate conditions and the type of crop grown
are BMPs always the same
no, BMPs will be location-specific because they depend on soil and climate conditions and the type of crop grown
