N-acetylcysteine increased nitrogen-induced rice yield

Sarwar, MJ1, Mohd Nozulaidi1, Mohd Khairi1

1Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, 22200, Besut, Terengganu, Malaysia


N-acetylcysteine (NAC) biosynthesized reduced glutathione (GSH) which maintains redox homeostasis in plants under normal and stressful conditions. To justify the effects of NAC on rice production, we measured yield parameters, chlorophyll (Chl) content, minimum Chl fluorescences (Fo), maximum Chl fluorescences (Fm), quantum yield (Fv/Fm), net photosynthesis rate (Pn), photosynthetically active radiation (PAR) and relative water content (RWC). Four treatments, namely, N1G0 {nitrogen (N) with no NAC}, N1G1 (N with NAC}, N0G0 (no N and no NAC) and N0G1 (no N but with NAC) were arranged as completely randomized design with five replications. Nitrogen significantly increased yield and yield parameters of rice plants. Moreover, NAC treatment increased panicle numbers, filled grains per panicle and yield of rice plants. Nitrogen significantly increased Chl content, Chl fluorescence parameters (Fm, Fv/Fm ratio) and Pn in leaves of the rice plant regardless of N treatments. NAC significantly increased RWC in leaves of N-untreated rice plant. In conclusion, this study suggests that NAC might enhance rice yield through modulating physiological functions of rice plants.

The effect of ‘Double High Agriculture’ on nitrogen losses from crop production to coastal water in China

Ang Li1, Maryna Strokal1, Carolien Kroeze1,2, Zhaohai Bai3, Lin Ma3

1 Environmental Systems Analysis Group, Wageningen University, Droevendaalsesteeg 3, Wageningen, The Netherlands, 6708 PB, ang.li@wur.nl
2 Water Systems and Global Change Group, Wageningen University, Droevendaalsesteeg 3, Wageningen, The Netherlands,  6708 PB

3 Key Laboratory of Agricultural Water Resource, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, Huaizhong Road 286, Shijiazhuang, Hebei 050021, China.


‘Double High Agricultural’ (DHA) is a nutrient management strategy focusing on increasing nitrogen (N) and phosphorus (P) use efficiencies, while also increasing crop yields. DHA may thus reduce losses of nutrients to the environment. We quantified the impact of DHA on N inputs to rivers and coastal seas in the year 2050. To this end, we applied the Global NEWS (Nutrient Export from WaterSheds) model. Two scenarios were developed based on two different agricultural practice of DHA: 1) The Integrated Soil-crop Systems Management (ISSM) scenario which assumes a 30% lower synthetic fertilizer application and 30% higher crop yields; 2) The ISSM-MR scenario, which is as ISSM, but assumes increased Manure Recycling in crop production, leading to lower synthetic fertilizer use. The results indicate that river export of dissolved inorganic N (DIN) and dissolved organic N (DON) in the ISSM scenario are about 10% lower than in the reference scenario. In ISSM-MR river export of DIN is about 30% lower than in the reference scenario.

Closing the nitrogen supply and demand gap using legume residue combined with fertiliser nitrogen input

Pilar Muschietti-Piana1,2, Therese McBeath1,2, Ann M. McNeill1, Pablo A. Cipriotti3 and Vadakattu Gupta2,

1 School of Agriculture, Food & Wine, The University of Adelaide, SA5005, E mail: pilar.muschiettipiana@csiro.au

2 CSIRO Agriculture & Food, CSIRO Agricultural Systems, Waite Campus, PB 2, Glen Osmond, Adelaide SA, 5064

3 School of Agriculture, University of Buenos Aires, Av. San Martin 4453, Ciudad Autónoma de Buenos Aires, C1417DSE


In low-rainfall wheat cropping systems, low crop uptake of nitrogen (N) has been linked to asynchrony in soil-N supply through mineralisation. This is especially true on sandy soils of SE Australia which have a low-N supply capacity. When N released from soil and residues is insufficient, and/or the timing of biological supply is not well matched with crop demand, manipulating N supply using fertiliser applications becomes vital to achieve yield potential. The aim of this study was to measure the timing of N supply with crop N uptake for wheat following wheat-residues and wheat following lupin-residues under two N fertiliser rates in a low-rainfall sandy soil environment. In each residue-type site, plants and deep soil samples to rooting depth were collected at sowing and at 5 key wheat growth stages. Plants were analysed for N content, above-ground biomass and grain yield at maturity. All soil samples were analysed for gravimetric water content and mineral-N. The combination of lupin residues with a high fertiliser N rate increased soil mineral-N at the time of high demand, promoted plant growth and wheat N uptake. In a dry season, the additional N supplied as fertiliser at early stages was a key input to support an increase in wheat yield potential. Responses in N uptake throughout the growing season indicate that there remains a demand for fertiliser N following legume-N residue in this environment, but fertiliser N inputs remain risky as indicated by the lack of significant yield increase in a low rainfall growing season.

The effects of intensification on Nitrogen Dynamics and Losses on Diversified Organic Vegetable Farms

Debendra Shrestha1, Krista Jacobsen2, Ole Wendroth3

1University of Kentucky, Ag. Science Bldg. N 308, Lexington, KY, 40546-0091, dsh243@uky.edu 

2 University of Kentucky, Ag. Science Bldg. N 308, Lexington, KY, 40546-0091

3 University of Kentucky, Ag. Science Bldg. N 1100, Lexington, KY 40546-0091


Nitrogen (N) is the main limiting nutrient, and is both a great driver of yield as well as agriculture’s impact on the environment. Organic farming systems are subject to N losses and have less predictable N dynamics than conventional systems. The objective of this study is to compare the N dynamics and key loss pathways in three farming systems, including two organic systems, representing a gradient of intensification (characterized by quantity of inputs, and the frequency of tillage and fallow periods) in Kentucky, USA. We have grown spring planted table beet (Beta vulgaris), summer planted green pepper (Capsicum anuum), and fall planted collard green (Brassica oleracea var. medullosa). Soils were sampled monthly for soil mineral N (NH4+ and NO3) at 0-15 cm, 15-30, and 30-50 cm depths. Trace gas fluxes (N2O and CO2) were measured weekly using a FTIR-based field gas analyzer. The results of this study showed the higher N2O and CO2 fluxes at the time of fertilizer application and tillage, at the beginning of the crop season.

Moringa Oleifera leaves and fertiplus affect nitrogen status and garden egg yield in Nigeria Savanna and rainforest soils.

A. Kekong1*, A. Ali2, T. O. Ojikpong1 and N. B. Ibrahim2

1-Cross River University of Technology, Obubra Campus

2- University of Agriculture, Makurdi, Benue State

*Corresponding author; email:matikekong@gmail.com


The dynamics of Nitrogen in manures has remained a challenge in the environment.  A field study was conducted at a rainforest and savannah locations in Nigeria during the 2009 and 2010 cropping seasons to evaluate effects of Moringa oleifera leaves and Fertiplus manure on soil total N and  yield of garden egg. A  factorial combination of two garden egg varieties (Gilo and Kumba) and Moringa( 5, 10, 20 t ha-1); Fertiplus( 1,2,3 t ha-1 ) with a     control   giving 14 treatments,within 3 replicates.  Results show that the manures increased soil total N from 30-90 days, with the highest increase from Moringa leaf 20 t ha-1 while the control showed a decline in total N. All manure rates significantly (P < 0. 05) increased yield of Solanum aethiopicum  varieties over the control. Moringa 20 t ha-1 produced highest fruit yield (7.22 t ha-1 and 6.68t ha-1 ) in 2009 and 10.37 t ha-1  and 9.17 t ha-1) in 2010 for Makurdi and Obubra respectively. The yields were significantly (t <0.05) higher in Makurdi than Obubra in both years.  Moringa leaf (20 t ha-1 ) is a good source of N for sustainable production of garden egg in Nigeria Rainforest and   savannah soils.

Nitrogen use efficiency for green onion (Allium fistulosum) in sands of South Central Coastal Vietnam using 15N-labelling

Truc T T Do1, Richard W Bell2, Nga P N Doan3, Surender Mann2

1 The Institute of Agricultural Sciences for southern Vietnam, 121 Nguyen Binh Khiem St., district 1, Ho Chi Minh city, 70000, Vietnam. http://iasvn.org. truc.dtt@iasvn.org

2 School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, 6150, Western Australia, Australia.

3 Center for Nuclear Techniques, Ho Chi Minh city, Vietnam.


The recovery of nitrogen (N) from N fertilizer is generally poor. Increasing N use efficiency (NUE) on sands is particularly challenging due to low nutrient storage and high percolation rate of water through the root zone.  The objectives of the experiment were to assess the change in fertilizer NUE for onion with clay or sugarcane residue amendments, and using 15N labelled urea to determine the recovery of N in the plant-soil system in a deep sand. The experiments were carried out in Ninh Thuan province, Vietnam  under flood or sprinkler irrigation. The 15N-labelled urea was applied to 0.72 m2 mini-plots at 134 kg N/ha and 10.16 % N atom excess. Clay-rich soil or bentonite were applied to raise clay content to 25 g/kg  and sugarcane residues were applied at 30 t/ha.

Fertilizer supplied 47.5 to 50.5 % the onion N demand, however, this represented only 3.8 to 19 % of fertilizer N applied. Sugarcane residue was more effective than clay and bentonite additions while sprinkler irrigation increased NUE compared to flood irrigation. After harvesting onion, 19 to 24 % of fertiliser N was found in 0-20 cm top soil. Despite the increases in NUE with sugarcane residue, clay-rich soil or bentonite, 63 to 73 % of fertiliser N was lost from the soil-plant system. In addition to using sprinkler irrigation on sands, we suggest that adding clay and organic materials in combination with postponed application of N fertiliser or fertigation may be needed to further increase soil N retention and fertilizer NUE.

Reducing nitrous oxide emissions from sugarcane soil with legume intercropping

Monica Elizabeth Salazar Cajas1, Nicole Robinson1, Adam Royle2, Lawrence Di Bella2, Weijin Wang3, Marijke Heenan3, Steven Reeves3, Susanne Schmidt1, Richard Brackin1

1 School of Agriculture and Food Sciences, The University of Queensland, QLD, 4072 Brisbane, Australia; email: monica.salazarcajas@uq.net.au

2 Herbert Cane Productivity Services Limited, 181 Fairford Rd, Ingham QLD 4850, Australia

3 Department of Science, Information Technology and Innovation, 41 Boggo Road, Dutton Park, QLD 4102 Australia


Australian sugarcane cropping has low nitrogen (N) use efficiencies, largely due to a mismatch of early-season N fertiliser application and later season peak crop N demand, in combination with poor soils and wet climate. To address the problem of N losses via run-off, leaching and N2O emissions, the sugarcane industry is evaluating several avenues. One approach is to improve N use efficiency (NUE) by reducing the use of vulnerable-to-loss N fertiliser, supplementing crop needs with biologically fixed N via sugarcane-legume intercropping. In an optimised system, decomposing legumes would deliver N to sugarcane, synchronised with sugarcane’s long N accumulation phase. We hypothesised that legume intercropping in combination with lower N fertiliser rates will reduce N losses (N2O emissions were quantified here) but not sugar yields. Here we report on one of several field trials with sugarcane grown as monoculture or intercropped with legumes at full N fertiliser or lowered rates (67 or 41% of full N). In the second year of implementation and compared to full N fertiliser, N2O emissions were reduced by 50 to 70% in the 67% N treatments irrespective of legume presence. Highest sugarcane biomass was achieved with full-N rate, 67% N, and 67% N + soybean intercropping. Sugarcane production was reduced in 67% N + mung bean intercropping, 41% N and zero N treatments. Sugar yield was variable but statistically similar across all treatments. These early results indicate that evaluation across different growing regions, fertiliser rates and planting times are needed to optimise sugarcane-legume intercropping systems.

Alternative N application strategies for reduced N2O emissions in flood-furrow irrigated cotton

Graeme Schwenke1, Annabelle Mcpherson2

1 NSW Department of Primary Industries, 4 Marsden Park Road, Tamworth, NSW, 2340, www.dpi.nsw.gov.au, Email graeme.schwenke@dpi.nsw.gov.au

2 NSW Department of Primary Industries, 4 Marsden Park Road, Tamworth, NSW, 2340, www.dpi.nsw.gov.au, Email annabelle.mcpherson@dpi.nsw.gov.au


The large inputs of N fertiliser needed for high-yielding irrigated cotton can potentially lead to substantial emissions of the greenhouse gas, nitrous oxide (N2O). We compared the impact on N2O emissions of three alternative strategies for applying the required amount of N to a commercial flood-furrow irrigated cotton crop. Compared to applying all N fertiliser pre-sowing, splitting the application between pre-sowing and in-season applications led to temporal differences in the N2O emitted, but there was no cumulative difference over the whole season. Similarly, altering the placement of the pre-sowing N fertiliser band from the non-irrigated side of the hill to the irrigated side of the hill led to a spatial difference in the N2O emission pattern, but no cumulative effect was observed. Almost all N2O emissions occurred in response to the first three of eight irrigation events, with the emissions after the second and third irrigations only observed where additional N was applied as water-run urea. The mostly low-intensity rainfall during this growing season had little impact on N2O emitted. Future research should focus on minimising N2O losses from the first irrigation, either through further reducing pre-plant N rates or by using a nitrification inhibitor with the pre-plant N application.

Mitigating indirect N2O emission from Japanese agricultural soils by reducing nitrogen leaching and runoff

Sadao Eguchi1,2, Nanae Hirano1, Shin-Ichiro Mishima1, Kazunori Minamikawa1

1 Institute for Agro-Environmental Sciences NARO (NIAES), Kannondai 3-1-3, Tsukuba, Ibaraki 305-8604, Japan

2 E-mail sadao@affrc.go.jp


Indirect nitrous oxide (N2O) emission from Japanese agricultural soils is accounted as comparable to direct N2O emission derived from inorganic or organic nitrogen (N) fertilizers in Japan. This paper tries to evaluate the mitigation potential of indirect N2O emission by reducing N leaching and runoff in different land uses at different prefectures in Japan. We used the national scale agricultural activity data of different prefectures from 1985 to 2005 and the N leaching and runoff monitoring data in Japan published after 1980. The N leaching and runoff values in vegetable and tea fields under various improved agricultural practices such as organic fertilizer application, slow release fertilizer application with reduced N application rate, cover cropping for green manure, etc., showed about 25% to 30% lower values from those under conventional practices, suggesting that such improved practices are similarly effective to mitigate indirect N2O emission from agricultural fields.

Progress in quantifying coastal N2O emissions in order to close the (terrestrial) biogenic nitrogen budget

Naomi S. Wells1*, Damien Maher1, Dirk Erler1, Vera Sandel1, Badin Gibbes2, Matt Hipsey3, James Udy4, Bradley Eyre1

1Centre for Coastal Biogeochemistry, Southern Cross University, Lismore, NSW, Australia

2School of Civil Engineering, University of Queensland, Brisbane, QLD, Australia

3School of Earth and the Environment, University of Western Australia, Crawley, WA, Australia

4Healthy Waterways, Brisbane, QLD, Australia

*Corresponding author: naomi.wells@scu.edu.au


Aquatic nitrous oxide (N2O) emissions are both a poorly constrained component of the global greenhouse gas budget and a rarely quantified loss pathway during transport of reactive nitrogen (N) from land to sea. Quantification of N2O losses from coastal environments are particularly vital, as these regions are both biogeochemical hotspots and subject to dramatic increases in N loading from urbanisation and upstream agricultural intensification. This study aimed to link spatial intensive measurements of water-atmosphere N2O fluxes with biogeochemical controls across a land-use intensity gradient. We used recently developed cavity enhanced laser absorption spectroscopy to obtain quasi continuous (1 sec-1) measurements of dissolved N2O across the salinity gradient in eight sub-tropical estuaries subjected to varying land-use intensities. Land use had a dramatic effect: N2O fluxes from estuaries surrounded by >60% woody vegetation were an order of magnitude lower than from those surrounded by <30% woody vegetation, and the estuary mouth created a net N2O sink only in the four least impacted systems. The fact that N2O fluxes, but not nitrate concentrations, peaked at the freshwater-saltwater interface (1-5 psu) in seven of eight surveyed estuaries suggested that benthic processes, not point source pollution, controlled N2O emissions. The fact that groundwater infiltration did not drive N2O peaks supports the idea that benthic biology, rather than hydrology, regulates estuarine N2O losses. As N2O did not track the spatial patterns of the commonly measured N species (ammonium, nitrate), an accurate catchment N balance could only be achieved via directly measuring estuarine N2O emissions.