Plant uptake of organic N has been studied for more than a century and has also been covered by several recent and older reviews.
In spite of the numerous studies showing the capacities of plants to absorb organic N compounds through roots, and demonstrations of how plants acquire such compounds also in field settings, the issue is still a matter of intense debate.
Download : Uptake of organic nitrogen by plants
PERMOHONAN HAK PERLINDUNGAN VARIETAS TANAMAN
DESKRIPSI VARIETAS BARU
Kepada Yth.:
Kepala Pusat Perlindungan Varietas Tanaman
Kantor Pusat Deprtemen Pertanian, Gd. E, Lt. 3
Jl. Harsono RM No. 3,
Ragunan, Jakarta Selatan (12550)
Asal-usul dan Proses Perakitan Varietas:
Selengkapnya : Deskripsi Varietas Baru
Urea (NH2CONH2) is of great importance to the agriculture industry as a nitrogen-rich fertiliser.
Urea is made from ammonia and carbon dioxide. Ammonia is synthesised from hydrogen (from natural gas) and nitrogen (from the air). The ammonia and carbon dioxide are fed into the reactor at high pressure and temperature, and the urea is formed in a two step reaction:
2NH3 + CO2 <=>NH2COONH4 (ammonium carbamate)
NH2COONH4 <=> H2O + NH2CONH2 (urea)
The urea contains unreacted NH3 and CO2 and ammonium carbamate. As the pressure is reduced and heat applied the NH2COONH4 decomposes to NH3 and CO2. The ammonia and carbon dioxide are recycled.
More : download urea (pdf file)
Although silicon (Si) is not recognized an essential element for the growth of higher plants, it has been proved that Si is beneficial or quasi-essential to plants. The beneficial effects are particularly distinct on plants exposed to various forms of biotic and abiotic stress. Currently, silicate fertilizers are extensively used in many countries, especially in Asian, African and Latin American countries. Silicon is now playing ever-increasingly important roles in the sustainability of agriculture. In the last two decades, the roles of silicon in plants and agriculture have been widely recognized by scientists, government officials and farmers throughout the world due to the great advancements in both basic and applied research on silicon. The Si community has also grown up, with 200 participants in the fourth conference, which is doubled more than in the first session.
Silicon in agriculture included chemical and geochemical characterization of silicon in soil and its availability, physiological and molecular mechanisms of silicon uptake and transport, Si-enhanced plant growth and development, Si-enhanced tolerance to biotic and abiotic stresses, silicon fertilizer manufacturing and marketing etc. The theme of the 5th International Conference on Silicon in Agriculture is “Silicon and Sustainable Agricultural Development”. Rapid progress and great breakthrough have been achieved in the research on the role of silicon in plant biology and agriculture over the last decade. This conference will provide a forum for the distinguished scientists, colleagues, students, fertilizer producers and consumers to present their most recent findings and achievements, and to exchange their valuable experiences with their international partners.
Kesuburan Tanah 