Archive for the category: Cropping systems and nitrogen efficiency

Sarwar, MJ¹, Mohd Nozulaidi¹, Mohd Khairi¹

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

Abstract

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.

Ang Li¹, Maryna Strokal¹, Carolien Kroeze^1,2, 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.

Abstract

‘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.

Pilar Muschietti-Piana^1,2, Therese McBeath^1,2, 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

Abstract

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.

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

Abstract

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.

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

Abstract  

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.

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.

Abstract

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.