Fallowing and wheat production in southern NSW

1966 ◽  
Vol 6 (22) ◽  
pp. 233 ◽  
Author(s):  
GD Kohn ◽  
RR Storrier ◽  
EG Cuthbertson

The response of wheat to the length of fallow, to the number of cultivations, and to pre-planting chemical control of weeds on high fertility soils was determined under winter rainfall conditions at Wagga Wagga, New South Wales, over four years commencing 1960-61. Length of fallow had little influence on the conservation of rainfall except in 1961-62, when approximately twice the average summer rainfall added 1.8 inches of soil moisture per acre 48 inches. Long fallow increased available nitrogen accumulation, but this did not increase yield over either the mechanically prepared shorter fallows, or pre-planting chemical weed control. This was due to losses during the autumn-winter period of some of the excess mineral nitrogen that accrued during the long fallow. High mineral nitrogen concentrations also occurred during the summer on weed-free, uncultivated soils. Grain yield after a single autumn cultivation was as high as after a long fallow except in 1961-62. In this year the long fallow (September to May) significantly increased yields over all other treatments. The absence of any positive yield response to the application of 60 to 80 lb nitrogen an acre to short fallows suggests that mineral nitrogen concentrations were generally adequate for grain production. The addition of nitrogen to long fallows often depressed yields. The dependence of grain yield on adequate weed control is illustrated by a highly significant negative correlation (r = -0.849 ; P<0.001) of grain yield with weed growth. It is concluded that in the Wagga Wagga environment weed control is more important than moisture conservation and mineral nitrogen accumulation through fallowing.

Soil Research ◽  
1996 ◽  
Vol 34 (2) ◽  
pp. 289 ◽  
Author(s):  
SA Hossain ◽  
WM Strong ◽  
SA Waring ◽  
RC Dalal ◽  
EJ Weston

Mineral nitrogen release following legume-based cropping systems for restoring the fertility of a Vertisol and the yield response and N uptake of subsequent wheat crops was studied. Legume phases of pastures, including a 4 year grass+legume ley, and lucerne and medic leys (~1 year) were terminated in October 1988 or 1989 and rotated with wheat. Chickpea-wheat rotations matched those of lucerne and medic leys. Mineral N accumulations during a subsequent fallow period were determined by core sampling to 1.5 m in October, February and May. Grain yield and N uptake of wheat enabled comparisons of the fertility restorative effects of the various systems relative to continuous wheat cropping. Averaged for two fallow periods, increases in mineral N down to 1.2 m depth were 93, 91, 68, and 37 kg/ha following grass+legume, lucerne and medic leys, and chickpea, respectively, compared with the continuous wheat treatment. Wheat yields were generally lower in 1989 (1.85–2.88 t/ha) than in 1990 (2.08–3.59 t/ha) following all leys and crops due to seasonal conditions. There was a grain yield increase of 0.11 and 0.52 t/ha in 1989 and 1.23 and 1.26 t/ha in 1990 following lucerne and medic leys, respectively and 0.85 t/ha in 1990 following a 4 year grass+legume ley. Following chickpea there was a yield increase of 0.81 and 1.36 t/ha in 1989 and 1990 respectively. Nitrogen uptake by wheat was increased by 40 and 49 kg/ha in 1989 and 48 and 58 kg/ha in 1990 following lucerne and medic leys respectively and 63 kg/ha in 1990 following a 4 year grass+legume ley. Following chickpea N uptake by wheat was increased by 27 and 32 kg/ha in 1989 and 1990 respectively. Grain protein concentration of wheat was substantially higher following all pasture leys (11.7–15.8%) than following wheat (8.0–9.4%) or chickpea (9.4–10.1%). Therefore, there was substantial evidence of the effectiveness of pasture leys in soil fertility restoration, as reflected in mineral N, yield response and N uptake by subsequent wheat crops.


1977 ◽  
Vol 28 (2) ◽  
pp. 165 ◽  
Author(s):  
RA Fischer ◽  
I Aguilar ◽  
DR Laing

Experiments to study the effect of grain number per sq metre on kernel weight and grain yield in a high-yielding dwarf spring wheat (Triticum aestivum cv. Yecora 70) were conducted in three seasons (1971–1973) under high-fertility irrigated conditions in north-western Mexico. Crop thinning, shading and carbon dioxide fertilization (reported elsewhere), and crowding treatments, all carried out at or before anthesis, led to a wide range in grain numbers (4000 to 34,000/m2). Results indicated the response of grain yield to changing sink size (grains per sq metre), with the post-anthesis environment identical for all crops each year, and with all but the thinner crops intercepting most of the post-anthesis solar radiation. Kernel weight fell linearly with increase in grain number over the whole range of grain numbers studied, but the rate of fall varied with the season. Grain yield, however, increased, reaching a maximum at grain numbers well above those of crops grown with optimal agronomic management but without manipulation. It was concluded that the grain yield in normal crops was limited by both sink and post-anthesis source. There was some doubt, however, as to the interpretation of results from crowded crops, because of likely artificial increases in crop respiration on the one hand, and on the other, in labile carbohydrate reserves in the crops at anthesis. Also deterioration in grain plumpness (hectolitre weight) complicates the simple inference that further gains in yield can come from increased grain numbers alone.


1960 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
SA Waring ◽  
LJH Teakle

The level of mineral nitrogen in the soil under fallow and crop was measured for the years 1951 to 1953. Relationships of mineral nitrogen at planting to yield and nitrogen content of wheat grain and straw were examined. Values for nitrate nitrogen at the end of the fallow period ranged most commonly from 10 to 20 µg/g in the surface 2 ft and from 0 to 10 µg/g at 2-4 ft. Approximately one-third of the sites showed an increase from the third to the fourth foot. One site showed extremely high values throughout the profile, particularly at 3-4 ft where a value of 127 µg/g was recorded. Values for ammonia nitrogen were most commonly in the range of 0-3 µg/g . Under the growing crop, mineral nitrogen declined for most depths in the period from planting up to September or October, after which there was little further change to harvest. Uptake of mineral nitrogen was normally greatest from the surface 2 ft of soil. Below 3 ft there were two groups of sites. One group showed moderate to high uptake and the second group low uptake. The low uptake in the latter group provides a reason for mineral nitrogen accumulation below 3 ft at some sites. Mineral nitrogen to 4 ft at planting averaged 126 lb/ac, excluding the one site with exceptionally high values. This was double the mean value of 63 lb/ac for nitrogen recovered in grain and straw, for crops planted in May-June. These figures, combined with trends in the soil under crop, suggest that most of the nitrogen used by the crop was derived from that in the soil at planting. Correlations between mineral nitrogen at planting and grain yield were mostly non-significant, suggesting that in general nitrogen was not an important factor limiting yield. Low grain yield and protein percentage were recorded at a number of sites which had been cultivated more than 50 years.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kelly A. Nelson ◽  
Peter P. Motavalli ◽  
William E. Stevens ◽  
John A. Kendig ◽  
David Dunn ◽  
...  

Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S), 0-0-25-17, 3-18-18-0, and 5-0-20-13) and additive rates (2.2, 8.8, and 17.6 kg K ha−1) on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1in a low-yield year (2005) depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K(P=0.03), S(P=0.03), B(P=0.0001), and Cu(P=0.008)concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.


2010 ◽  
Vol 28 (1) ◽  
pp. 103-111 ◽  
Author(s):  
M.S. Lima ◽  
P.S.L. Silva ◽  
O.F. Oliveira ◽  
K.M.B. Silva ◽  
F.C.L. Freitas

The interference imposed the by weeds on corn decreases practically all vegetative characteristics. As consequence, the green ear and grain yield are also reduced. Losses due to the fall armyworm (Spodoptera frugiperda) attack can reduce corn grain yield up to 34%. In general, weed and insect control issues are addressed separately in research papers. Nevertheless, interaction between weeds and insects may exist. This study aimed to evaluate green ear and corn grain yield response to weed and fall armyworm control. A completely randomized block design with split-plots and five replicates was adopted. Corn cultivar AG 1051 was grown under weedy conditions or with control by hand hoeings performed at 20 and 40 days after planting. Fall armyworm control (applied to subplots) was performed with sprays of water (control), deltamethrin (5g active ingredient ha-1); neem oil, at 0.5% (diluted in water), and neem leaf extract at 5%. Each product was sprayed three times, at seven-day intervals, starting at the 7th day after planting, using 150 L ha-1 of the tank solution. Dry mass of the above-ground part, internode diameter, leaf length, leaf width, leaf area, green ear yield and grain yield of corn were reduced due to the lack of weed control. Fall armyworm control in the weeded plots did not influence green ear yield and grain yield, except green mass of marketable, husked ears, which was reduced when the caterpillar was not controlled. Without weed control, neem extracts and deltamethrin sprays provided highest yields of number and total weight of green ears with husks, number and weight of marketable ears with husks and number of marketable ears without husks. The best results for husked ear mass and for grain yield were obtained with neem extract and deltamethrin, respectively.


1987 ◽  
Vol 27 (5) ◽  
pp. 661 ◽  
Author(s):  
GK McDonald ◽  
WK Gardner

Two experiments were conducted in 1983 and 1984 in the Hamilton district in south-western Victoria, which examined, in 1983, the interaction of cultivars of different maturity with sowing date and, in 1984, the interaction of soil waterlogging with anthesis date. In the first experiment the grain yield of Isis and Condor were not significantly (P = 0.05) affected when sowing was delayed from 18 April to 13 May despite greater DM yield at anthesis of the April sown crops (44% with Isis and 8 1 % with Condor). Early sowing resulted in early flowering and in Condor 25% fewer grains per ear. When the effect of anthesis date on grain yield was examined in 1984 at a poorly drained site (Hamilton) and a nearby better drained site (Tabor), it was found that early flowering caused yield reductions of 46 and 25%, respectively. The reduced yield at Hamilton was caused by fewer grains per ear and a lower kernel weight. Grain yield was found to be associated with the severity of waterlogging during the 30 days before anthesis. For each 1% decline in the mean air-filled porosity of the surface soil at this time, yield was reduced by 0.29 t/ha (r2 = 0.83; P< 0.05). When the soils became waterlogged, nitrogen concentrations in the plant tops declined to low levels between stem elongation and anthesis. The need to avoid waterlogging damage during stem elongation in spring may necessitate anthesis being delayed beyond the time currently recommended for the district.


1970 ◽  
Vol 10 (46) ◽  
pp. 604 ◽  
Author(s):  
GD Kohn ◽  
RR Storrier

Wheat (CV. Heron) sown on clover-improved soils at Wagga Wagga, New South Wales, over the period 1961 to 1965 showed a general reduction in yield and an increase in grain protein percentage with delay in sowing. Grain yield decreased by 3.7 per cent for each week's delay in sowing after the end of April and the rate of grain protein increase ranged from 0.09 to 0.56 per cent for each week's delay, depending on seasonal conditions. This grain protein increase was accompanied by a reduced kernel size which resulted in a decrease in grain protein yield of 12.5 lb an acre for each week's delay in sowing. The reduced grain yield with later sowings was associated with less efficient use of soil moisture the post-flowering period. Although the cumulative evapotranspiration of early sown crops was about two inches greater than that for late sown crops in mid-spring, all sowings reduced the soil moisture potential to -15 bars to a depth of four to five feet at maturity. However, the late sown crops matured more rapidly with a reduction in all yield components. Changes in soil mineral nitrogen concentration during the growing season indicated that there Was adequate nitrogen available for all sowings. In two years mineralization of soil organic nitrogen occurred under the crops and contributed significantly to the crops requirement. In a third year mineral nitrogen losses from the soil could not be accounted for by plant uptake.


2020 ◽  
Vol 1 (1) ◽  
pp. 43-48
Author(s):  
Bisheshwor Prasad Pandey ◽  
Tanka Prasad Kandel

Recent decades have seen many changes in agricultural production systems in Nepal, such as increased mechanization for harvesting of major cereal crops, which leaves a large volume of crop residue in the field, increased herbicide application for weed control, and increased adoption of reduced tillage systems. In this study, we compared the effects of tillage, rice residue and weed managements on yield and yield attributes of wheat cultivated under rice-wheat rotation in the Southern Plain (Terai) region of Nepal. The study was conducted during the wheat growing seasons (November through April) of 2013–2014, 2014–2015 and 2015–2016 in Rupandehi district. The experiment was deployed in a split-split plot design with tillage system as main plot [conventional tillage (CT) and zero tillage (ZT)], residue removal management as a sub-plot [whole residue retained (WR), partial residue retained (PR) and no residue retained (NR)], and weed management as a sub-sub plot [(manual weeding (MW) and chemical weeding (CW)], replicated three times. Analysis of variance was applied to the yield and yield attributes of wheat for fixed and interaction effects. Averaged across the years, the CT system (2.4 t ha–1) had significantly higher yield than ZT (2.2 t ha–1) but the difference was not consistent in all study years. While rice residue retention did not influence grain yield in Year1, WR produced greatest and NR produced lowest yield in Year2 and Year3, indicating potential yield increase in wheat following the whole rice residue retention in the long run. Grain yield did not significantly vary with weed management method, suggesting that manual weed control can be as effective as herbicide in weed management in wheat agroecosystem in the Southern Plains (Terai) region of Nepal.


2016 ◽  
Vol 52 (4) ◽  
pp. 635-653 ◽  
Author(s):  
PATRICK MUSINGUZI ◽  
PETER EBANYAT ◽  
JOHN STEPHEN TENYWA ◽  
TWAHA ALI BASAMBA ◽  
MOSES MAKOOMA TENYWA ◽  
...  

SUMMARYSoil Organic Carbon (SOC) is a major indicator of soil fertility in the tropics and underlies variability in crop response to mineral fertilizers. Critical SOC concentrations that interact positively with N fertilizer for optimal crop yield are less understood. A study was conducted on a Ferralsol in sub-humid Uganda to explore the critical range of SOC concentrations and associated fractions for optimal maize (Zea maysL.) yield response to applied mineral N fertiliser. Maize grain yield response to N rates applied at 0, 25, 50 and 100 kg N ha−1in 30 fields of low fertility (SOC<1.2%), medium fertility (SOC = 1.2–1.7%) and high fertility (SOC>1.7%) was assessed. Soil was physically fractionated into sand-sized (63–2000 µm), silt-sized (2–63 µm) and clay-sized (<2 µm) particles and SOC content determined. Low fertility fields (<1.2% SOC) resulted in the lowest response to N application. Fields with >1.2% SOC registered the highest agronomic efficiency (AE) and grain yield. Non-linear regression models predicted critical SOC for optimal yields to be 2.204% at the 50 kg N ha−1rate. Overall, models predicted 1.9–2.2% SOC as the critical concentration range for high yields. The critical range of SOC concentrations corresponded to 3.5–5.0 g kg−1sand-sized C and 9–11 g kg−1for clay-sized C.


1983 ◽  
Vol 23 (120) ◽  
pp. 103
Author(s):  
JE Pratley

The control by herbicides of an infestation of Amsinckia hispida and toadrush (Juncus bufonius) in wheat was investigated at Wagga Wagga, New South Wales, during 1979 and 1980. Bromoxynil, bromoxynil+MCPA, terbutryne and methabenzthiazuron+2,4-D were used in both years, dicamba+MCPA in 1979, and dicamba and experimental herbicide DPX4189 (GleanTM�) in 1980. All herbicides reduced weed densities and improved crop yields. Terbutryne gave greatest control of weed populations, in excess of 98% in both years. Grain yield was more than doubled in each case. GleanTM produced the highest grain yield in 1980 although weed control was not as good as from some other herbicides. However, the undersown pasture legumes, particularly subterranean clover, had poorer survival from this herbicide. Dicamba and dicamba+MCPA were inferior to the other chemicals in the control of these weeds.


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