A follow up of this meeting was held in Malta between the 8th
and 9th October 2013, which was attended by three Israeli researchers from the
Volcani Centre. During the meeting held at the Government Research Centre in
Għammieri, four presentations on water application and results obtained on NPK
studies were delivered by the Israeli partners. Various officials from the
Directorate of Agriculture and PARKS joined in discussions with the Israeli
partners, particularly on nitrogen application and the use of wastewater in
agriculture as well as landscaping.
A discussion on the application of natural manure in soil
cropped up and the Israeli partners argued that since the nitrogen present in
dry livestock manure is not soluble, it is not available for the plant before
it passes through mineralisation process. Nitrates in manure are released only
after being irrigated and initial breakdown by micronutrients starts to take
place. Once available to the plant, nitrogen is immediately taken up and
excessive nitrate application at that stage may become critical. If manure is
applied during the summer months, 50% of the nitrogen is lost through
volatisation of ammonium by winter. To be more effective, application of manure
must be done in a similar manner as inorganic fertilizer, to ensure nitrogen
uptake by the plants through the roots. Moreover, when irrigating, it is
important to take into account the amount of fertilizer applied, the plant
requirements and the season during which this is done.
In a presentation on the water resources in Israel, it was
explained that a large emphasis is being placed on the use of recycled waste
water since there is an issue with water scarcity, low precipitation and high
water consumption. Nevertheless there is evidence that long-term use of treated
water for edible crops results in a decreased yield and an increase of chloride
and nitrate pollution. Thus, one has to properly follow waste water
management guidelines issued by the World Health
Organisation.
Apart from using recycled water for irrigation, desalination is
a novel and effective means to maximize water use efficiency and crop
productivity in Israel. In another presentation, the importance to consider
water salinity in soil and available to the plant was discussed. By using
lysemeter experiments on banana plants, Israeli researchers are finding that
salinity may not be dependent solely on chlorine but also on root volume, plant
type and water quality. It is interesting to note that difference in fruit
yield and salt uptake by plants relate to water
quality.
A presentation on Israeli regulations for manure recycling and
nitrogen application was delivered by one of the Israeli partners. Such
regulations are in place to balance plant requirements with environment needs
and regulate the composting of manure to negate odours and food contamination.
Moreover, Israeli regulations dictate that only class A sludge may be used in
agriculture while the maximum permitted Nitrate application is that of
500kg/ha/year, which is high when compared with the 170kg/ha/year in the
European Union. In Israel, compost facilities are permitted but are
regulated to be located at a minimum of 300 metres from residential areas.
During this meeting, a discussion on the Nitrates Action Plan
took place and the Israeli partners argued that rainwater leaching in Malta is
not as great an issue as in other northern European countries. Malta, with its
dry summers and low levels of precipitation in Winter, should not literally
apply a legislation applied for countries with high rainfall and restricted to
a growing season in summer. Crop rotation is also another important factor in
that certain crops fix nitrogen in the soil and may require far less nitrogen
application, as well as contributing to improvements in soil structure. They
suggested that research using lysemeter should be conducted in Malta to
determine local needs and effects of nitrates and other minerals on crops.
Another presentation was delivered on the application of sludge
as fertilizer substitutes for field crops. Research in Israel has shown that
sludge can replace fertilizers, improve soil structure, and its use in
agriculture is the best method to deal with its disposal, reducing incineration
and placement of sludge in landfills. Nevertheless, sludge application in
agriculture should follow strict regulations as its application is dependent on
acceptable levels of metals and nutrients which may be used in agriculture.
Following the meeting at the Government Research Centre in
Għammieri, the Israeli partners visited a greenhouse farm in Imġarr, in which
the farmer cultivates fresh tomatoes for the local market. They discussed
various technical issues with the farmer on fertilization methods,
experimentation with various tomato varieties and irrigation methods. This
field visit was followed by a visit to a dairy farm in San Ġwann, where the
farmer invested in robotic milking technology and explained the farm management
practices in Malta as well as compared to that being applied in Israel.
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