Sugarcane straw preservation results in limited immobilization and improves crop N-fertilizer recovery

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Current knowledge indicates that sugarcane straw is a short-term sink of fertilizer nitrogen (N) due to N immobilization during the decomposition process. This study aimed to determine whether sugarcane straw removal from the field benefits the N-fertilizer recovery by plant (NRP), and if legume cultivation will further improve NRP. Half of a field was planted with sunn hemp (Crotalaria spectabilis) and half was left fallow. In the second ratoon, treatments with 0, 50, and 100% of sugarcane straw maintenance levels were installed, receiving 120 kg ha−1 N over straw. A microplot of ammonium nitrate labeled with 1.99% atoms 15N was included. NRP was quantified at 92, 164, and 264 days after fertilization (DAF). At harvest (264 DAF), soil samples and straw (<4 mm and >4 mm fractions) were collected to determine N-fertilizer recovery in the soil (NRS) and in the straw (NRSt). Maintaining 50 and 100% of straw improved NRP over the sugarcane cycle. NRP was not improved by crop rotation cultivation and NRS averaged 50% in the entire soil profile. NRSt at harvest averaged 1–3% in the 50% and 100% straw levels. Contrary to the current view, N-fertilizer immobilization in the straw was negligible and keeping straw could improve NRP. The findings indicate that increasing N rates in green cane trash blanket system to compensate for the N-fertilizer immobilization is not necessary, and that straw removal for bioenergy production will change the short-term demand for N-fertilizer.
OriginalsprogEngelsk
TidsskriftBiomass and Bioenergy
Antal sider10
ISSN0961-9534
DOI
StatusUdgivet - jan. 2021
Eksternt udgivetJa

ID: 327392074