Nitrogen timing and rate effects on growth and grain yield of delayed permanent-water rice in south-eastern Australia

2014 ◽  
Vol 65 (9) ◽  
pp. 878 ◽  
Author(s):  
B. W. Dunn ◽  
T. S. Dunn ◽  
H. G. Beecher
Keyword(s):  
Plant Growth ◽  
Grain Yield ◽  
Management Practices ◽  
Management Practice ◽  
Water Productivity ◽  
N Application ◽  
South Eastern ◽  
Eastern Australia ◽  
N Management ◽  
South Eastern Australia

The need for continual improvement in water productivity of rice farming has led to the development of delayed permanent (continuous) water (DPW) irrigation practice for drill-sown rice in south-eastern Australia. Current rice-growing practices have the crop flooded for most, or all, of its growing period, whereas DPW has reduced the period of flooding during the vegetative phase, resulting in significant water savings. The changed water-management practice required nitrogen (N) management practices to be investigated, because traditional N application timings and rates may no longer be suitable. Six experiments were conducted over three rice-growing seasons, 2010–11, 2011–12 and 2012–13, on two soil types in south-eastern Australia. Nitrogen applications at sowing, early tillering, mid-tillering and pre-PW were investigated at different rates and split-timing combinations. In the third season, three current commercial semi-dwarf rice varieties, Reiziq, Sherpa and Langi, were investigated for their growth and grain yield using different N treatments under DPW management. Nitrogen applied with the seed at sowing increased vegetative plant growth but did not increase grain yield, whereas N applied at early tillering had no significant impact on plant growth or grain yield. Nitrogen applied at mid-tillering often increased plant growth but did not lead to increased grain yield over treatments that received all N before PW application at 18–22 days before panicle initiation. When rice is managed under DPW, all N should be applied in one application, before the application of PW. The results from this research show that applying 100 kg N ha–1 before PW for rice grown under DPW was the best N-management option for the experimental fields. All three varieties grew and yielded well under the practice of DPW and responded similarly to N application rates and timings.

Nitrogen balances in temperate perennial grass and clover dairy pastures in south-eastern Australia

2007 ◽  
Vol 58 (12) ◽  
pp. 1167 ◽  
Author(s):  
R. J. Eckard ◽  
D. F. Chapman ◽  
R. E. White
Keyword(s):  
Ammonium Nitrate ◽  
Management Practices ◽  
Perennial Grass ◽  
Dairy Farms ◽  
Nutrient Inputs ◽  
N Losses ◽  
Total N ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Nitrogen (N) fertiliser use on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concurrently, imports of supplementary feed onto dairy farms have increased, adding further nutrients to the system. These trends raise questions about the environmental effects of higher nutrient inputs to dairy farms. To gauge possible effects, annual N balances were calculated from an experiment where N inputs and losses were measured for 3 years from non-irrigated grass/clover pastures receiving either no N fertiliser (Control) or 200 kg N/ha applied annually as ammonium nitrate or urea. Estimated total N inputs, averaged over the 3 years, were 154, 314, and 321 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively, while N outputs in meat and milk were 75, 99, and 103 kg N/ha.year, respectively. The corresponding calculated N surplus was 79, 215, and 218 kg N/ha.year for the 3 treatments, respectively, and the ratio of product N/total-N inputs for the 3 treatments ranged from 50% in the control to 32% for both N treatments. Total N losses averaged 56, 102, and 119 kg N/ha.year, leaving a positive N balance of 23, 112, and 99 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. The ratio of product N/total-N inputs or the N surplus may be useful in monitoring the efficiency of conversion of N into animal products and the potential environmental effect at a whole-farm scale. However, additional decision support or modelling tools are required to provide information on specific N losses for a given set of conditions and management inputs. Given the large range in N losses there is opportunity for improving N-use efficiency in dairy pastures through a range of management practices and more tactical use of grain and N fertiliser.

Mapping change in key soil properties due to climate change over south-eastern Australia

Soil Research ◽  
2019 ◽  
Vol 57 (5) ◽  
pp. 467 ◽  
Author(s):  
Jonathan M. Gray ◽  
Thomas F. A. Bishop
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Management Practices ◽  
Climate Models ◽  
Carbon Accounting ◽  
Depth Interval ◽  
Soil Conditions ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Climate change will lead to altered soil conditions that will impact on plant growth in both agricultural and native ecosystems. Additionally, changes in soil carbon storage will influence carbon accounting schemes that may play a role in climate change mitigation programs. We applied a digital soil mapping approach to examine and map (at 100-m resolution) potential changes in three important soil properties – soil organic carbon (SOC), pH and sum-of-bases (common macro-nutrients) – resulting from projected climate change over south-eastern Australia until ~2070. Four global climate models were downscaled with three regional models to give 12 climate models, which were used to derive changes for the three properties across the province, at 0–30 and 30–100 cm depth intervals. The SOC stocks were projected to decline over the province, while pH and sum-of-bases were projected to increase; however, the extent of change varied throughout the province and with different climate models. The average changes primarily reflected the complex interplay of changing temperatures and rainfall throughout the province. The changes were also influenced by the operating environmental conditions, with a uniform pattern of change particularly demonstrated for SOC over 36 combinations of current climate, parent material and land use. For example, the mean decline of SOC predicted for the upper depth interval was 15.6 Mg ha–1 for wet–mafic–native vegetation regimes but only 3.1 Mg ha–1 for dry–highly siliceous–cropping regimes. The predicted changes reflected only those attributable to the projected climate change and did not consider the influence of ongoing and changing land management practices.

Effect of sowing time on yield and agronomic characteristics of wheat in south-eastern Australia

1995 ◽  
Vol 46 (7) ◽  
pp. 1381 ◽  
Author(s):  
H Gomez-Macpherson ◽  
RA Richards
Keyword(s):  
Grain Yield ◽  
Flowering Time ◽  
Barley Yellow Dwarf Virus ◽  
Maximum Yield ◽  
Sowing Date ◽  
High Yield ◽  
Sowing Time ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The main environmental constraints to the yield of dryland wheat in south-eastern Australia are: a low and erratic rainfall throughout the growing season, the chance of frost at flowering time, and high temperatures during the grain-filling period. The aims of this work were threefold. Firstly, to determine which sowing period minimizes these constraints and results in the highest yields. Secondly, what is the optimum flowering time for a given sowing date so that maximum yield is achieved. The third aim was to determine whether any crop characteristic was associated with high yield or may limit yield in the different sowings. The experiments were conducted at three sites in New South Wales that were representative of dry (Condobolin) and cooler and wetter (Moombooldool, Wagga Wagga) sites in the south-eastern wheatbelt. In this study several sets of isogenic material, involving a total of 23 genotypes, that were similar in all respects except for flowering time, were sown early (mid-April and early May), normal (mid to late May) and late (June to mid July). Characteristics of the highest-yielding lines in each experiment are presented. The average flowering time of the highest yielding lines in all sowings had a range of only 12 days at the driest site, but a range of over 20 days at the coolest and wettest site. The optimum anthesis date (day of year, y) was related to sowing date (day of year, doy) at the cooler sites such that: y = 245+0.32 doy (r2 = 0.86) and at Condobolin, y = 253+0.19 doy (r2 = 0.91). Optimum anthesis date expressed in thermal time (�C days) after sowing (y) was related to sowing time (doy) as follows: y = 2709 -8-3 doy (r2 = 0.84). It is suggested that these relationships are likely to be quite robust and should hold true for similar thermal environments in eastern Australia. There was little variation in grain yield between the earliest sowing in mid-April (108 doy) and sowings throughout May (up to 147 doy). Grain yield declined 1.3% per day that sowing was delayed after late May. Aboveground biomass was substantially higher in early sown crops. However, this did not translate into higher yields. From the evidence presented it is argued that the principal reason that greater yields were not obtained in the early sowings, particularly in the April sowing, was the greater competition for assimilates between the growing spike and the elongating stem. It is suggested that a way of overcoming this competition is to genetically shorten the stems of winter wheats. This should capitalize on the considerable advantages in terms of water use efficiency that early sowing offers and result in greater yields. Barley yellow dwarf virus, although present at the cooler, wettest site in one year, was more frequent in the later sowings than in the early sowing and was not likely to have contributed to the lower than expected yields in the early sowings.

Longevity of wheat yield response to lime in south-eastern Australia

1997 ◽  
Vol 37 (5) ◽  
pp. 571 ◽  
Author(s):  
D. R. Coventry ◽  
W. J. Slattery ◽  
V. F. Burnett ◽  
G. W. Ganning
Keyword(s):  
Grain Yield ◽  
Soil Ph ◽  
Wheat Yield ◽  
Yield Response ◽  
South Eastern ◽  
Initial Application ◽  
Eastern Australia ◽  
Phosphorus Fertiliser ◽  
Lime Application ◽  
South Eastern Australia

Summary. A long-term experiment in north-eastern Victoria has been regularly monitored for wheat yield responses to a range of lime and fertiliser treatments, and the soil sampled for acidity attributes. Substantial grain yield increases have been consistently obtained over a period of 12 years with a single lime application. Lime applied at 2.5 t/ha in 1980 was still providing yield increases of 24% with an acid-tolerant wheat (Matong, 1992 season) and 79% with an acid-sensitive wheat (Oxley, 1993 season) relative to no lime treatment. The 2 wheat cultivars responded differently to phosphorus fertiliser, with the acid-sensitive wheat less responsive to phosphorus fertiliser in the absence of lime. The use of a regular lime application applied as a fertiliser (125 kg lime/ha) with the wheat seed gave only a small grain yield increase (8% Matong, 16% Oxley), despite 1 t/ha of lime applied over the 12-year period. Liming the soil at a rate of 2.5 t/ha (1980) initially raised the soil pH by about 1.0 unit and removed most soluble aluminium (0–10 cm). However, after 12 years of crop–pasture rotation after the initial 2.5 t lime/ha treatment the soil pH had declined by 0.7 of a pH unit and exchangeable aluminium was substantially increased, almost to levels prior to the initial application of lime. Given the continued yield responsiveness obtained following the initial application of lime, this practice, rather than regular applications of small amounts of lime, is recommended for wheat production on strongly acidic (pHw < 5.5) soils in south-eastern Australia.

Corrigendum to: Mapping change in key soil properties due to climate change over south-eastern Australia

Soil Research ◽  
2019 ◽  
Vol 57 (7) ◽  
pp. 805
Author(s):  
Jonathan M. Gray ◽  
Thomas F. A. Bishop
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Management Practices ◽  
Climate Models ◽  
Carbon Accounting ◽  
Depth Interval ◽  
Soil Conditions ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Climate change will lead to altered soil conditions that will impact on plant growth in both agricultural and native ecosystems. Additionally, changes in soil carbon storage will influence carbon accounting schemes that may play a role in climate change mitigation programs. We applied a digital soil mapping approach to examine and map (at 100-m resolution) potential changes in three important soil properties – soil organic carbon (SOC), pH and sum-of-bases (common macro-nutrients) – resulting from projected climate change over south-eastern Australia until ~2070. Four global climate models were downscaled with three regional models to give 12 climate models, which were used to derive changes for the three properties across the province, at 0–30 and 30–100 cm depth intervals. The SOC stocks were projected to decline over the province, while pH and sum-of-bases were projected to increase; however, the extent of change varied throughout the province and with different climate models. The average changes primarily reflected the complex interplay of changing temperatures and rainfall throughout the province. The changes were also influenced by the operating environmental conditions, with a uniform pattern of change particularly demonstrated for SOC over 36 combinations of current climate, parent material and land use. For example, the mean decline of SOC predicted for the upper depth interval was 15.6 Mg ha–1 for wet–mafic–native vegetation regimes but only 3.1 Mg ha–1 for dry–highly siliceous–cropping regimes. The predicted changes reflected only those attributable to the projected climate change and did not consider the influence of ongoing and changing land management practices.

Net nitrogen balances for cool-season grain legume crops and contributions to wheat nitrogen uptake: a review

2001 ◽  
Vol 41 (3) ◽  
pp. 347 ◽  
Author(s):  
J. Evans ◽  
A. M. McNeill ◽  
M. J. Unkovich ◽  
N. A. Fettell ◽  
D. P. Heenan
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
N2 Fixation ◽  
Grain Legumes ◽  
N Balance ◽  
Grain Legume ◽  
Soil N ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The removal of nitrogen (N) in grain cereal and canola crops in Australia exceeds 0.3 million t N/year and is increasing with improvements in average crop yields. Although N fertiliser applications to cereals are also rising, N2-fixing legumes still play a pivotal role through inputs of biologically fixed N in crop and pasture systems. This review collates Australian data on the effects of grain legume N2 fixation, the net N balance of legume cropping, summarises trends in the soil N balance in grain legume–cereal rotations, and evaluates the direct contribution of grain legume stubble and root N to wheat production in southern Australia. The net effect of grain legume N2 fixation on the soil N balance, i.e. the difference between fixed N and N harvested in legume grain (Nadd) ranges widely, viz. lupin –29–247 kg N/ha (mean 80), pea –46–181 kg N/ha (mean 40), chickpea –67–102 kg N/ha (mean 6), and faba bean 8–271 kg N/ha (mean 113). Nadd is found to be related to the amount (Nfix) and proportion (Pfix) of crop N derived from N2 fixation, but not to legume grain yield (GY). When Nfix exceeded 30 (lupin), 39 (pea) and 49 (chickpea) kg N/ha the N balance was frequently positive, averaging 0.60 kg N/kg of N fixed. Since Nfix increased with shoot dry matter (SDM) (21 kg N fixed/t SDM; pea and lupin) and Pfix (pea, lupin and chickpea), increases in SDM and Pfix usually increased the legume’s effect on soil N balance. Additive effects of SDM, Pfix and GY explained most (R2 = 0.87) of the variation in Nadd. Using crop-specific models based on these parameters the average effects of grain legumes on soil N balance across Australia were estimated to be 88 (lupin), 44 (pea) and 18 (chickpea) kg N/ha. Values of Nadd for the combined legumes were 47 kg N/ha in south-eastern Australia and 90 kg N/ha in south-western Australia. The average net N input from lupin crops was estimated to increase from 61 to 79 kg N/ha as annual rainfall rose from 445 to 627 mm across 3 shires in the south-east. The comparative average input from pea was 37 to 47 kg N/ha with least input in the higher rainfall shires. When the effects of legumes on soil N balance in south-eastern Australia were compared with average amounts of N removed in wheat grain, pea–wheat (1:1) sequences were considered less sustainable for N than lupin–wheat (1:1) sequences, while in south-western Australia the latter were considered sustainable. Nitrogen mineralised from lupin residues was estimated to contribute 40% of the N in the average grain yield of a following wheat crop, and that from pea residues, 15–30%; respectively, about 25 and 15 kg N/ha. Therefore, it was concluded that the majority of wheat N must be obtained from pre-existing soil sources. As the amounts above represented only 25–35% of the total N added to soil by grain legumes, the residual amount of N in legume residues is likely to be important in sustaining those pre-existing soil sources of N.

The relationships between land uses, soil management practices, and soil carbon fractions in South Eastern Australia

2014 ◽  
Vol 197 ◽  
pp. 41-52 ◽  
Author(s):  
S.M.Fazle Rabbi ◽  
Matthew Tighe ◽  
Annette Cowie ◽  
Brian R. Wilson ◽  
Graeme Schwenke ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Management Practices ◽  
Soil Management ◽  
Land Uses ◽  
Carbon Fractions ◽  
South Eastern ◽  
Eastern Australia ◽  
Soil Carbon Fractions ◽  
South Eastern Australia

scholarly journals Grain Yield Response of Corn (Zea mays L.) to Nitrogen Management Practices and Flooding

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 348
Author(s):  
Taylor E. Dill ◽  
Steven K. Harrison ◽  
Steven W. Culman ◽  
Alexander J. Lindsey
Keyword(s):  
Grain Yield ◽  
Management Practices ◽  
Zea Mays L ◽  
Management Strategies ◽  
Nitrogen Management ◽  
Growth And Yield ◽  
Yield Response ◽  
N Application ◽  
Nitrate N ◽  
N Management

Flooding can reduce corn growth and yield, but nitrogen (N) management practices may alter the degree to which plants are negatively impacted. Damage caused by flooded conditions may also affect the utilization of a post-flood N application to increase yield. The objectives of this study were to evaluate how pre-plant and pre-plant plus post-flood N applications contribute to corn growth and yield following flood conditions and to quantify the partial return of employing different N management strategies in the event of a flood. A field study was conducted in Ohio using four flood durations (FD; 0, 2, 4, or 6 days initiated at V4 to V5) and three N management practices (0 kg N ha−1, 134 kg N ha−1 applied pre-plant, and 134 pre-plant + 67 kg N ha−1 applied post-flooding). Application of 134 kg N ha−1 increased yield compared to 0 kg N ha−1 by 65%, 68%, 43% and 16% for 0 d, 2 d, 4 d, and 6 d FD, respectively; the application of 134 + 67 kg N ha−1 increased grain yield compared to 134 kg N ha−1 by 7%, 27%, 70%, or 55% for 0 d, 2 d, 4 d, or 6 d FD, respectively. Partial return analysis produced similar results to those for grain yield. Results suggest that in regions prone to early-season flooding, additional N applied post-flood can improve yield and partial return compared to the application of pre-plant alone at a lower rate or no N. Results indicate that total soil nitrate-N levels two weeks after flood initiation may serve as a good predictor of yield.

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