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Mount Maunganui, New Zealand

Boyd L.M.,The New Zealand Institute for Plant and Food Research Ltd | Barnett A.M.,The New Zealand Institute for Plant and Food Research Ltd | Johnstone P.R.,The New Zealand Institute for Plant and Food Research Ltd | Searle B.P.,The New Zealand Institute for Plant and Food Research Ltd | And 2 more authors.
Acta Horticulturae | Year: 2013

New Zealand is geographically isolated from many of its key markets where kiwifruit are sold. To retain a competitive edge, the New Zealand kiwifruit industry needs to produce high-quality fruit whilst minimising production costs. In the market, high quality means uniform size, acceptable taste and good storage potential. Consumer acceptability has been linked to fruit dry matter concentration (DMC; dry weight as a proportion of fresh weight (FW)). Nitrogen (N) fertiliser application can affect canopy vigour, fruit size, DMC and storage potential. Therefore applying the right amount of N at the right time could have financial benefits to growers. We discuss some of the factors that need to be considered when managing N fertiliser application and give preliminary results from a long-term N-input experiment we have set up on a numbers of 'Hayward' orchards in the North Island of New Zealand. The main findings were that increasing N application could increase fruit FW, meaning that less fruit needed to be thinned off during the season, giving the potential for higher crop loads to be produced. Conversely increased N input reduced fruit DMC. The future challenge is to maintain a balance between fruit FW, crop load and DMC, and to determine which attributes are the best predictors of how much N to apply to individual orchards. Source

Khan I.,Gomal University | Zaman M.,Ballance Agri Nutrients Ltd | Khan M.J.,Gomal University | Iqbal M.,Gomal University | Babar M.N.,Gomal University
Journal of Soil Science and Plant Nutrition | Year: 2014

A field experiment was conducted to assess the efficiency of urea applied with urease inhibitor [N-(n-butyl) thiophosphoric triamide (nBTPT- trade-name Agrotain®), and organic compound (Cytozyme) in minimizing abiotic plant stress in a potato (Solanum tuberosum L.) in Dera Ismail Khan, Pakistan in 2010-2011. The nine treatments of control (no N or Cytozyme), urea applied at 200 and 300 kg N ha-1, Agrotain treated urea applied at 200 and 300 kg N ha-1, urea-200+Cytozyme, urea-300+Cytozyme, Agrotain treated urea-200+Cytozyme, and Agrotain treated urea-300+Cytozyme, were replicated 5 times. Potato growth, yield and quality were significantly influenced by urea applied with Agrotain and Cytozyme. Agrotain treated-urea-200 with Cytozyme resulted in maximum plant survival (91%), plant height (48 cm), plant canopy (61 cm) and the number of stems per plant (3.9 stems) compared to urea alone. Agrotain-treated urea applied at 200 and 300 kg N ha-1 increased potato yield by 46% and 42%, respectively, compared to urea alone. Cytozyme with urea @ 200 and 300 kg N ha-1 increased potato yield by 53% and 35%, respectively, comparing to potato crops receiving urea at the two N rates. Tuber yield improved by 14% when Cytozyme was applied with Agrotain-treated urea at 200 kg N ha-1. Cytozyme and urea applied with Agrotain treated urea-300+Cytozyme produced 33% of large tubers, followed by 31% of medium tubers with urea-200 and Agrotain treated urea-200+Cytozyme. Our results demonstrate that urea applied at 200 kg N ha-1 with either Agrotain or with Cytozyme have the most potential to enhance potato yield. Source

Edmeades D.C.,AgKnowledge Ltd. | Morton J.D.,Ballance Agri Nutrients Ltd | Waller J.E.,Agresearch Ltd. | Metherell A.K.,Ravensdown Fertiliser Co operative Ltd | And 2 more authors.
New Zealand Journal of Agricultural Research | Year: 2010

Field-trial data from a database comprising records of 804 potassium (K) fertiliser trials were used to define the production functions relating exchangeable soil K (quick test K (QTK) 0-75 mm) to the relative response to fertiliser K applications, for the major soil groups in New Zealand. For all soil groups for which there were sufficient data, the production functions were generally flat in the range QTK 5-10, and thus the estimated relative pasture production at QTK 5 and QTK 10 were similar. The critical QTK levels to achieve 97% maximum production were relatively well defined, being 6 (5-8) for sedimentary soils (brown and pallie) and brown soils, and 7 (5-10) for pumice soils. The data for the allophanic soils were unstable and the best estimate was 6 (5-10). For the remaining soils groups (podzols and raw soils, organic, recent and gley soils) for which there was much less data, the relationships were essentially flat over the range QTK 2-10. The probability of pasture responses to applied K increased as soil QTK decreased from 10. For the sedimentary and volcanic soils (including both allophanic and pumice) the probability was about 70-80% at soil QTK <2. The comparable probabilities were 50-60% for the recent and gley soils, and 30-43% for the podzols and raw soils. A feature of the response functions was that some trials were not responsive to fertiliser K despite having low soil QTK. In most cases this could not be attributed to soil K reserves as measured by the soil TBK test (sodium tetra-phenol-boron extractable which measures exchangeable K plus plant-available but non-exchangeable K). Other possible reasons for this feature in the data are discussed, including uptake of K from below the soil sampling depth and the temporal effects of clover responses to applied K. Soil K buffer capacities-the amount of fertiliser K over and above maintenance required to increase soil QTK by 1 unit (ΔK)-ranged from 50 to > 150 kg K ha -1 (average 124) for sedimentary soils. For some soils (developed organic soils, gleyed soils and podzols), fertiliser K had very little effect on QTK (0-75 mm). It is not clear whether these differences are due to differences in leaching of K from the sampling depth, differences between soils in their ability to absorb and retain applied K or indeed the result of errors in the measurement of this parameter. Estimated maintenance K requirements (i.e. the amount of applied K required to maintain soil QTK levels) increased with increasing soil QTK from 4 to 10, from 0-150 kg K ha -1 yr -1 to 100-300 kg K ha -1 yr -1 in situations where losses of K were extreme due to the removal of all harvested clippings. Given the uncertainties in predicting K responses and the amount of fertiliser K required to correct K deficiency, practical suggestions are offered as to how best to diagnose and manage soil K deficiency. Areas for future research to improve the prediction of pasture responses to fertiliser K are also included. © 2010 The Royal Society of New Zealand. Source

Ni K.,CAS Nanjing Institute of Soil Science | Ni K.,University of Chinese Academy of Sciences | Ding W.,CAS Nanjing Institute of Soil Science | Zaman M.,Ballance Agri Nutrients Ltd | And 4 more authors.
Biology and Fertility of Soils | Year: 2012

Nitrous oxide emission (N 2O) from applied fertilizer across the different agricultural landscapes especially those of rainfed area is extremely variable (both spatially and temporally), thus posing the greatest challenge to researchers, modelers, and policy makers to accurately predict N 2O emissions. Nitrous oxide emissions from a rainfed, maize-planted, black soil (Udic Mollisols) were monitored in the Harbin State Key Agroecological Experimental Station (Harbin, Heilongjiang Province, China). The four treatments were: a bare soil amended with no N (C0) or with 225 kg N ha -1 (CN), and maize (Zea mays L.)-planted soils fertilized with no N (P0) or with 225 kg N ha -1 (PN). Nitrous oxide emissions significantly (P < 0. 05) increased from 141 ± 5 g N 2O-N ha -1 (C0) to 570 ± 33 g N 2O-N ha -1 (CN) in unplanted soil, and from 209 ± 29 g N 2O-N ha -1 (P0) to 884 ± 45 g N 2O-N ha -1 (PN) in planted soil. Approximately 75 % of N 2O emissions were from fertilizer N applied and the emission factor (EF) of applied fertilizer N as N 2O in unplanted and planted soils was 0. 19 and 0. 30 %, respectively. The presence of maize crop significantly (P < 0. 05) increased the N 2O emission by 55 % in the N-fertilized soil but not in the N-unfertilized soil. There was a significant (P < 0. 05) interaction effect of fertilization × maize on N 2O emissions. Nitrous oxide fluxes were significantly affected by soil moisture and soil temperature (P < 0. 05), with the temperature sensitivity of 1. 73-2. 24, which together explained 62-76 % of seasonal variation in N 2O fluxes. Our results demonstrated that N 2O emissions from rainfed arable black soils in Northeast China primarily depended on the application of fertilizer N; however, the EF of fertilizer N as N 2O was low, probably due to low precipitation and soil moisture. © 2012 Springer-Verlag. Source

Li J.,CAS Shenyang Institute of Applied Ecology | Li J.,Agresearch Ltd. | Shi Y.,CAS Shenyang Institute of Applied Ecology | Luo J.,Agresearch Ltd. | And 5 more authors.
Biology and Fertility of Soils | Year: 2014

Applications of dairy farm effluents to land may lead to ammonia (NH3) volatilization and nitrous oxide (N2O) emissions. Nitrogen (N) transformation process inhibitors, such as urease inhibitors (UIs) and nitrification inhibitors (NIs), have been used to reduce NH3 and N2O losses derived from agricultural N sources. The objective of this study was to examine the effects of amending dairy effluents with UI (N-(n-butyl) thiophosphoric triamide (NBTPT)) and NI (dicyandiamide (DCD)) on NH3 and N2O emissions. Treatments included either fresh or stored manure and either fresh or stored farm dairy effluent (FDE), with and without NBTPT (0.25 g kg-1 N) or DCD (10 kg ha-1), applied to a pasture on a free-draining volcanic parent material soil. The nutrient loading rate of FDE and manure, which had different dry matter contents (about 2 and 11 %, respectively) was 100 kg N ha-1. Application of manure and FDE led to NH3 volatilization (15, 1, 17 and 0.4 % of applied N in fresh manure, fresh FDE, stored manure and stored FDE, respectively). With UI (NBTPT), NH3 volatilization from fresh manure was significantly (P < 0.05) decreased to 8 % from 15 % of applied N, but the UI did not significantly reduce NH3 volatilization from fresh FDE. The N2O emission factors (amount of N2O-N emitted as a percentage of applied N) for fresh manure, fresh FDE and stored FDE were 0.13 ± 0.02, 0.14 ± 0.03 and 0.03 ± 0.01 %, respectively. The NI (DCD) was effective in decreasing N2O emissions from stored FDE, fresh FDE and fresh manure by 90, 51 and 46 % (P < 0.05), respectively. All types of effluent increased pasture production over the first 21 days after application (P < 0.05). The addition of DCD resulted in an increase in pasture production at first harvest on day 21 (P < 0.05). This study illustrates that UIs and NIs can be effective in mitigating NH3 and N2O emissions from land-applied dairy effluents. © 2013 Springer-Verlag Berlin Heidelberg. Source

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