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Why use fertilisers??

Why use fertilisers??. Why do farmers apply fertiliser?. All living organisms require some basic chemical elements to function i.e. to build DNA , cells walls etc The major elements required are; nitrogen, phosphorus, potassium, sulphur, calcium and magnesium. Why do farmers use fertiliser?.

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Why use fertilisers??

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  1. Why use fertilisers??

  2. Why do farmers apply fertiliser? • All living organisms require some basic chemical elements to function i.e. to build DNA , cells walls etc • The major elements required are; • nitrogen, phosphorus, potassium, sulphur, calcium and magnesium

  3. Why do farmers use fertiliser? • To over come nutrient deficiencies • To replace nutrients transferred: • off farm in production i.e. milk, meat, wool,crops • to unproductive areas of the farm i.e. effluent ponds, tracks

  4. If any one of these elements is deficient • grass will not grow • or will not grow as well as it could

  5. What are the environmental problems associated with fertiliser application? • Phosphate runoff • Approximately 80% of the phosphate in our waterways comes from agricultural runoff • Nitrate leaching • A study in the late 80’s indicated that up to 20% of ground wells in Taranaki and Waikato had over 10mg/l nitrate • The recommended maximum level is 11.3mg/1

  6. These affect water quality • By causing algal blooms and excessive weed growth which • stops us drinking it • stops recreational activity • stops us eating the fish • and kills aquatic life

  7. How do excess nutrients get into waterways? • Direct application • animals depositing directly in waterways • fertiliser spreaders applying too close to waterways • Erosion • pugging & compaction • Runoff • surface runoff • sub-surface runoff • Leaching

  8. Nitrate Leaching • Dairy cattle numbers have gone from 2.9 million to 4.1 million in 2001 • N fertiliser use has gone from 117,000 tonnes of N in 92/93 to 333,000 tonnes in 01/02 • What are the current figures? • A cows urine patch contains the equivalent of 500-1000 kg N/ha

  9. Nitrate Leaching cont.. • At normal rates of application leaching losses from nitrogen fertilisers are typically 5-10% of nitrogen applied.

  10. What can be done to minimise the environmental effects One option - Design a fertiliser plan for each farms specific needs. • This includes: • Nutrient budgeting • GPS Soil & Herbage testing • Farm Environment Maps • Using environmentally fertilisers

  11. Sustain – an example of a more environmentally friendly fertiliser • Sustain is urea that has been coated in Agrotain & Sulphur. • Sustain reduces leaching losses of nitrogen. • And also reduces ammonia volatilisation losses to the atmosphere

  12. Sustain • Agrotain slows the breakdown of the urea. • Urea breaks down over 0-2 days • Sustain breaks down over 0-10 days • Slowing the breakdown of urea gives the plant more opportunity to take up nitrogen therefore leaving less nitrogen available to be leached.

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