P reduction (Phosphorus) Archives -

4.4. P removing filters

Aaron Swann / 21st June 2019

Adjust the composition of livestock diets to reduce the total intake of N and P per unit of production. Recent research has shown that animal feed can be formulated to reduce nitrogen (N) and
phosphorus (P) excretion without reducing animal performance (Utah State University Cooperative Extension, 2010; Shields and Orme-Evans, 2015) . The ideal protein concept is a feeding method in which crude protein levels are reduced and amino acids are supplemented in order to reduce N excretion. For reduction of P excretion, adding phytase to the diet has been shown to increase P availability to hogs and chickens.

1.5.1. Phosphorus Removal System

Aaron Swann / 21st June 2019

This passive filtration system was developed in the United States and is an outcome of a decade (1999 – 2009) of research by Drizo and co-workers on the use of steel slag aggregates (SSA) for P removal from wastewaters. The system is accepted in five states in the USA as the first and only conservation practice especially developed to reduce the amount of P from subsurface drain (tile) flows and other subsurface and surface P containing runoff outflows. Sources of agricultural outflows may include agricultural tile drains, ditches and animal heavy use areas such as milk-house wastewater, feed bunks, and silage leachate runoff.

1.4.1. Controlled Drainage

Aaron Swann / 21st June 2019

Major advantages of the controlled drainage system to compare conventional drainage system is a chance to adjust groundwater level to occasionally higher than by normal drainage thereby soil moisture increases especially during dry season and the drainage run is reduced. Enhanced plant water and nutrient intake, thus increasing yield. By controlled drainage farmer can affect fields water economy through out the year and diminish nutrient impact into watercourses.

2.1. Field Nutrient Budgeting

Aaron Swann / 21st June 2019

A Nutrient Management Plan (NMP) is a key BEMP strategy in running a farm to optimise crop yield and quality, minimize fertilizer input costs and protect soil and water (European Commission, 2018). The principles of nutrient management are simple and include:
• applying fertilizer only to make up the difference between what is there and what is required to achieve the target yield, which also ensures cost-effectiveness for the producer; and
• ensuring that the added nutrient is available to the crop.

1.3.1. No-till farming: direct drilling

Aaron Swann / 21st June 2019

In no-till farming seeding is done without tilling of the soil with direct seeding machine and it decreases soil erosion and nutrient runoff (N and PP). It is cost-effective method because yield loss is compensated by savings in fuel and work costs. The benefits of the methods will be shown in a time when soil structure improves naturally.

2.3. Precision nutrient application

Aaron Swann / 21st June 2019

The basics for precision nutrient application is to determine farm’s nutrient balances (at the farm gate, field and stable level). The balances are usually calculated for nitrogen (N), phosphorus (P) and potassium (K). The ideal situation is that the value of the field balance is close to zero, which means that the nutrient uptake of plants and the supply by fertilization are in ideal balance.

Agricultural University of Iceland Pilot Site

2.2. Crop rotation for efficient nutrien cycles

Aaron Swann / 21st June 2019

Optimized crop rotation is an element for efficient nutrient cycles and maintains good soil fertility to ensure high yields. Nitrogen-fixing plants will decrease the need for fertilizers and enhance economic and environmental sustainability of whole farm. Catch crops prevent soil erosion and reduce runoffs and also add organic matter content of soil. Increased biodiversity will give plants a better resistance and reduces demand for pesticides.

1.1. Soil Quality Assesment

Aaron Swann / 21st June 2019

Soil quality consists of physical, biological and chemical features. Soil structure, type and texture influence a lot in nutrient circulation, leaching and run-offs from the catchment basin. For example compaction caused by heavy machines and grazing reduce water infiltration capacity, root growth and nutrient uptake by plants and thus cause more surface run-offs into water bodies. In addition, soil degradation leads to inefficient use of fertilizers and causes loss of resources.

1.3. Conservation Tillage

Aaron Swann / 5th June 2019

Soil compaction can be prevented with an easy and inexpensive methods. Often the reason for soil compaction are too heavy machinery used on a field and wrong timing for cultivation activities. Unwanted impact of agricultural machinery can be compensated to some extent e.g. with adjustment of tire pressure and assuring moist condition of soil before working on a field. Ideal soil structure benefit by reduced need of fertilizing and improved buffering capability against extreme conditions.