Phosphate availability and phosphate needs of soils under Siratro pastures as assessed by soil chemical tests

1968 ◽  
Vol 8 (34) ◽  
pp. 561 ◽  
Author(s):  
RE White ◽  
KP Haydock

In field trials covering a range of soils and environmental conditions, the variation in soil equilibrium phosphate potentialSP accounted for 86 per cent of the variation in the percentage yield response of Siratro (Phaseolus atropurpureus) to phosphorus, compared to 72 per cent accounted for by the Olsen extraction, 51 per cent by Truog's and 38 per cent by Morgan's. The Truog and Morgan extractants gave improved correlations with phosphate uptake, but all four methods were poorly correlated with phosphate concentration in the plant. For the prediction of the soil's phosphate requirement for 90 or 95 per cent of the maximum yield, the Morgan method was superior to the equilibrium potentialSP, Olsen and Truog methods, and comparable to the quantity measurement P sorbed, derived from the soil's quantity-intensity (Q/I) relation at the minimum, non-limiting solution activity of 2.2 �M P : each accounted for 67 per cent of the variation in P required for 90 per cent of the maximum yield. The precision of the extractions in estimating P required decreased as the extractant/soil ratio and the extraction period increased. Of the conventional extractants, a method could be chosen that was well correlated with either P required (Morgan's) or plant relative yield (Olsen's), but none that was well correlated with both criteria. On the other hand, the measurement: of the one Q/I relation provided intensity (equilibrium potentialSP) and quantity (P sorbed) terms for the prediction, respectively, of a soil's phosphate availability and its phosphate needs for optimum plant growth.

2003 ◽  
Vol 54 (10) ◽  
pp. 957 ◽  
Author(s):  
A. G. Condon ◽  
F. Giunta

Transient waterlogging during winter and spring reduces wheat yield in many parts of southern Australia. Yield reductions from waterlogging are associated with reduced production and survival of tillers, fewer and smaller fertile tillers, and smaller grain size. Under favourable conditions, wheats that have the tiller-inhibition ('tin') gene produce a lower total number of tillers but a higher proportion of large, productive tillers and larger grains than wheats without this gene. These characteristics of restricted-tillering wheat may contribute to improved yield under transient waterlogging. We compared the growth and yield of the commercial variety Bodallin and 2 Bodallin backcross derivatives containing the 'tin' gene in 8 field trials grown on shallow, duplex soils in 1995 and 1996 at 3 locations in the south-west of Western Australia. Trials were sown at standard (1995) and standard and high (1996) seeding rates. Trial-mean yield ranged from 0.5 to 4.7 t/ha, depending on the occurrence and severity of waterlogging before anthesis and of soil water deficit before and after anthesis. Grain yield of the restricted-tillering (RT) lines averaged only c. 80% of Bodallin. At all sites and seeding rates the RT lines had fewer spikes per m2 (45% fewer, on average) but averaged 44% more grains per spike. In 1996 only, grain weight of the RT lines was 6% greater than of Bodallin. There was no evidence that the relative yield of the RT lines was greater at waterlogged sites than at other sites. Waterlogging reduced the number of fertile spikes of RT lines and of Bodallin to the same relative extent and differences in grains per spike and grain size had little effect on relative yields. Even though harvest index of the RT lines was slightly elevated in some environments, biomass production of the RT lines was low in all environments. We conclude that wheats with the 'tin' gene are unlikely to have a yield advantage under transient waterlogging unless their biomass production can match that of more freely tillering wheats.


1983 ◽  
Vol 23 (120) ◽  
pp. 38 ◽  
Author(s):  
PW Moody ◽  
GF Haydon ◽  
T Dickson

Grain yield response of soybean (Glycine max cv. Bragg) to applied phosphorus was measured at 19 experimental sites in the South Burnett region. The soil phosphorus supply factors of quantity, intensity, buffer capacity and rate were estimated by various soil chemical tests, and relative yield [(yield at nil applied phosphorus/maximum yield) x 100] regressed against these tests. The equilibrium phosphorus concentration-the intensity measure-accounted for the greatest percentage variation in relative yield (80%) and at 90% maximum yield was 0.014 �g P/ml. Phosphorus extracted by 0.01 M CaCl2 was highly correlated with the equilibrium phosphorus concentration (r2=0.93) and accounted for 73% of the variation in relative yield. Soil levels of calcium chloride-extractable phosphorus were interpreted as follows: < 0.044 �g P/g, response to phosphorus probable; 0.044 �g P/g to 0.058 �g P/g, response uncertain; > 0.058 �g P/g, response unlikely


1983 ◽  
Vol 55 (2) ◽  
pp. 163-178
Author(s):  
Into Saarela

Five potassium fertilization rates ranging from nil to 80 kg/ha/cut were compared over 2 to 3 years in field trials on timothy leys at nine sites between 61 and 65 °N. The grass was cut twice a year and the contents of nitrogen, potassium, calcium and magnesium in yields were determined. The soils were tested at the beginning and at the end of the trials. On four peat soils the yields over two years without potassium dressings were 34 to 66 % of the respective yields with adequate potassium fertilization. On humus soil the relative yield without potassium was 81 % and on fine sand soil 76 %. On two finesand tills rich inorganic matter the responce of timothy to potassium was 5 %. No significant yield response was obtained on silty clay. In accordance to the depletion of available soil reserves, the differences between the potassium rates increased with time. In average on the six most responsive soils the relative yields without potassium fertilization for the first four successive cuts were 88, 75, 58 and 45 %. For maximum yields, 60 to 80 kg/ ha potassium per cut was required on the organogenic soils and on the finesand, 20 kg/ha was enough on the other three mineral soils. The potassium contents of plants increased greatly, and the contents of nitrogen, calcium and magnesium decreased with increasing potassium fertilization rate. The magnesium content of grass rose to an unusually high level with severe potassium deficiencies. At the end of the trials the soils were quite exhausted of potassium, the subsurface layers being most exhausted. The critical plant potassium content varied from under 2 % to over 3 %. As the large variation was coupled with plant nitrogen, plant K/N ratio was a better indicator for potassium status of ley than plant K. Yield was likely to begin degreasing when the K/N ratio decreased under 1.


1996 ◽  
Vol 36 (7) ◽  
pp. 897 ◽  
Author(s):  
IR McPharlin ◽  
RC Jeffery ◽  
DH Pitman

The phosphorus (P) requirements of crisphead lettuce (Lactuca sativa L. cv. Oxley) was measured over 2 consecutive winter plantings using superphosphate that was freshly applied and applied 9 months before planting, at 0-600 kg/ha on a newly cleared Karrakatta sand of low natural P fertility. There was a significant (P<0.001) head yield response to level of applied P in both years. Phosphorus uptake by whole plants and plant shoots was related to level of applied P in Mitscherlich relationships (R2 = 0.88). Phosphorus recovery efficiency (fertiliser P uptake by shoots/P applied, both in kg/ha) by shoots decreased from 0.16 at 50 to 0.04 at 600 kg applied P/ha. Phosphorus recovery efficiency by whole plants (shoots plus roots) decreased from 0.18 at 50 to 0.05 at 600 kg P/ha. The level of freshly applied P required for either 95 or 99% of maximum relative yield over the 2 years (maximum yield, 86 t/ha) was 276 and 427 kg P/ha (Mitscherlich relationship, R2 = 0.95), respectively at <10 �g/g soil test P (newly cleared sites). The marketable yield was 82 and 95% of total yield at 276 and 427 kg P/ha respectively. Bicarbonate-soluble P extracted from the top 15 cm of soil was determined on residual P sites over 2 years where P was applied at 0-600 kg/ha. These soil test levels were related to head yield in a Mitscherlich relationship (R2 = 0.88). The critical soil test P values required for either 95 or 99% of maximum relative yield, over the 2 years, were 80 and 115 �g/g, respectively. Phosphorus in the wrapper leaf at early heading required for 95 or 99% of maximum yield was 0.59 � 0.03 and 0.61 � 0.03% (spline regression, R2 = 0.80), respectively. Soil and plant testing could be used to assist in reducing fertiliser costs, improving utilisation of freshly- and previously-applied fertiliser P by lettuce and reducing P losses to water systems on the Swan Coastal Plain in Western Australia.


1983 ◽  
Vol 63 (1) ◽  
pp. 113-123
Author(s):  
EMILE CHAMBERLAND

The objective of this study was to verify and improve the accuracy of fertilizer recommendations for growing cole crops on mineral soils. To achieve this end, 21 field trials were conducted on 12 soils during 1978–1981; of these trials, 13 were performed with late cabbage and Brussels sprouts and eight early cabbage and brocoli. The test crops were fertilized at four rates of N, P and K, and yield responses were related to soil test values. The Cate-Nelson iteration method was used to partition soils into three different classes according to their yield response to fertilization. Furthermore, polynomial and Mitscherlich equations were fitted to yield versus soil K and P data. These procedures suggested that fertilizer recommendations would be more precise by classifying these crops into early- and late-maturing groups. Accordingly, the recommended fertilization rates for soils containing a deficient or medium P supply were 70 and 80 kg P/ha for early and late crops, respectively. A clear yield response by early cabbage to K fertilization was indicated for soils containing a medium K supply; on these soils maximum yields would be achieved with an application of about 180 kg K/ha. On the other hand late cabbage and Brussels sprouts apparently only needed about 120 kg K/ha to achieve maximum yields on the same class of soils. While an increase in yields attributable to K fertilization is unlikely on soils containing a low and high K supply, a rate of 120 kg K/ha is nonetheless recommended to ensure maximum yield and maintain soil fertility levels. As regards N-fertilization, maximum yields early and late crop were produced with 160 and 180 kg N/ha, respectively. Key words: Fertilizer, N, P, K, vegetables, cabbages


2019 ◽  
pp. 240-244
Author(s):  
Elena Ghinda ◽  
Valery Khlebnikov ◽  
Natalia Treskina

Проведены исследования по применению регуляторов роста гиббереллина, мицефита, циркона и НВ-101 для обработки растений винограда сортов столового направления использования Лора и Аркадия в условиях Приднестровского региона. В период вегетации растения винограда обрабатывали дважды водными растворами следующих препаратов: гиббереллин (100 мг/л, St), мицефит в двух концентрациях -10 и 100 мг/л, циркон - 0,4 мл/л и НВ-101 - 0,05 мл/л. В статье приведены результаты двухлетних полевых опытов по изучению влияния регуляторов роста растений на урожайность и сахаристость сока ягод винограда. Установлена эффективность применения регуляторов роста в зависимости от климатических условий в период вегетации. Для винограда сорта Аркадия условия 2017 года были более благоприятными в сравнении с 2018 годом, что и обусловило более высокую урожайность контрольных растений в 2017 году - 19,8 против 12,8 т/га. Урожайность контрольных растений сорта Лора в годы исследований была практически на одном уровне и составляла 9,2-9,3 т/га. В более увлажненных условиях 2017 года обработка регуляторами роста оказалась неэффективной. Существенная прибавка урожая у сорта Аркадия - 4,2 т/га была получена лишь в варианте применения мицефита в концентрации 10 мл/л. Более эффективной была обработка регуляторами роста мицефит, циркон и НВ-101 в 2018 году, обеспечившая существенное увеличение урожайности с 12,8 до 15,5-20,4 т/га без снижения его качества. Средняя максимальная урожайность была отмечена в варианте обработки препаратом НВ-101. Обработка растений сорта Лора регуляторами роста обеспечила значительное повышение урожайности, но снизила сахаристость сока ягод. Наибольший эффект от их применения был отмечен в более засушливом 2018 году. Таким образом, применение регуляторов роста обеспечивает повышение урожайности и качества ягод винограда сортов Лора и Аркадия в зависимости от климатических условий года исследований.The study examined the effect of growth regulators gibberellin, micefit, zircon and NV-101 on table grapevine cultivars ‘Lora’ and ‘Arсadia’ in Transnistrian region. During vegetation grapevine plants were treated twice by aqueous solutions of the following preparations: gibberellin (100 mg/l, St), micefit in two concentrations-10 and 100 mg/l, zircon-0.4 ml/l and NV-101-0.05 ml/l. The paper summarizes findings of the two-year field trials conducted to study the effects of plant growth regulators on the yield and sugar content of the juice of grapes. The study established the effectiveness of growth regulators depending on climatic conditions during vegetation period. Year conditions of 2017 were more favourable for ‘Arcadia’ grapes as compared to 2018, which resulted in higher yields on control plants in 2017 - 19.8 t/ha. vs. 12.8 t/ha. The yield of control plants of ‘Lora’ vines was pretty much unchanged during the study years, and made 9.2 -9.3 t/ha. In the more humid conditions of 2017 treatment with growth regulators proved ineffective. Substantial positive yield response of ‘Arcadia’ grapes, specifically 4.2 t/ha, was obtained only in the trial variant of micefit application at a concentration of 10 ml/l. Treatment with growth regulators micefit, zircon and NV-101 in 2018 proved more effective, and demonstrated substantial increase from 12.8 to 15.5 - 20.42 t/ha without reducing the grape quality. The average maximum yield was recorded in the trial variant of treatment with NV-101 preparation. Treatment of ‘Lora’ with growth regulators provided a significant yield increase, but reduced sugar content in the berry juice. The strongest effect from the use of the preparations was registered in a more arid 2018. Thus, application of growth regulators increases productivity and quality of ‘Lora’ and ‘Arcadia’ grapevine cultivars depending on climatic conditions of the research year.


1998 ◽  
Vol 38 (1) ◽  
pp. 83 ◽  
Author(s):  
K. L. Freeman ◽  
P. R. Franz ◽  
R. W. de Jong

Summary. The response of cvv. Russet Burbank and Kennebec potatoes to different levels of residual and applied phosphorus (P) was compared on krasnozem and duplex soils in the Central Highlands of Victoria. Field experiments were conducted at 12 sites over 3 years to examine the effects of applied P (banded at planting) at rates up to 475 kg/ha on yield, petiolar P concentrations, tuber size, number of tubers/plant and specific gravity. The relationships between yield response and fertiliser P required to optimise yields with Olsen P and P adsorption isotherms were also determined. Application of P significantly (P<0.05) increased yields at 11 of the 12 sites for cv. Russet Burbank and at 6 of the 9 sites for cv. Kennebec. Based on data for all sites, there was a significant (P<0.001) Mitscherlich relationship between yield response to applied P and Olsen P. This relationship was significantly (P<0.05) different for each cultivar. The critical Olsen P concentration was 27 mg/kg for cv. Kennebec. However, for cv. Russet Burbank the relationship had not plateaued, although our Olsen P concentrations ranged from 5–46 mg/kg. For cv. Russet Burbank there was a significant (P<0.05) negative linear relationship between the amount of applied P required to achieve 95% of maximum yield and Olsen P concentrations. However, there was no significant (P>0.05) relationship between the amount of applied P required to achieve 99% of maximum yield and Olsen P concentrations. For these krasnozem and duplex soils, the predictive models of either yield response or the amount of applied P required to optimise yield, were not significantly (P>0.05) improved by including P sorptivity measures. At yield-responsive sites there were significant (P<0.05) changes in the proportion of tubers >280 g for both cultivars. However, the only quality parameter adversely affected by applied P was specific gravity. There were significant (P<0.05) Mitscherlich relationships between relative yield and petiole P concentrations for both cultivars. The following critical petiole P ranges have been proposed to assist in the assessment of the P status of cv. Russet Burbank crops in Victoria: 0.45–0.57% at a tuber length of 5–10 mm; 0.35–0.47% at a tuber length of 35–45 mm and 0.21–0.26% at a tuber length of 75–85 mm. The use of petiole sampling for assessment of the P status of potatoes before the 5–10 mm tuber stage is not recommended. The critical P range for cv. Russet Burbank was higher than the critical P range for cv. Kennebec at a 5–10 mm tuber length. The practical implications from this work are that Olsen P is a good indicator of a site’s potential yield response to applied P fertiliser. However, at those soil P concentrations where a yield response is expected, Olsen P is of little value to predict the amount of P fertiliser required to achieve maximum yields. We have established that separate calibration curves are required for cvv. Russet Burbank and Kennebec to define their critical Olsen P concentrations on krasnozem and duplex soils. This is the first work in Australia showing critical nutrient ranges for petiolar P over time in cv. Russet Burbank.


2004 ◽  
Vol 52 (2) ◽  
pp. 157-163
Author(s):  
C. U. Egbo ◽  
M. A. Adagba ◽  
D. K. Adedzwa

Field trials were conducted in the wet seasons of 1997 and 1998 at Makurdi, Otukpo and Yandev in the Southern Guinea Savanna ecological zone of Nigeria to study the responses of ten soybean genotypes to intercropping. The experiment was laid out in a randomised complete block design. The genotypes TGX 1807-19F, NCRI-Soy2, Cameroon Late and TGX 1485-1D had the highest grain yield. All the Land Equivalent Ratio (LER) values were higher than unity, indicating that there is great advantage in intercropping maize with soybean. The yield of soybean was positively correlated with the days to 50% flowering, days to maturity, plant height, pods/plant and leaf area, indicating that an improvement in any of these traits will be reflected in an increase in seed yield. There was a significant genotype × yield × location interaction for all traits. This suggests that none of these factors acted independently. Similarly, the genotype × location interaction was more important than the genotype × year interaction for seed yield, indicating that the yield response of the ten soybean genotypes varied across locations rather than across years. Therefore, using more testing sites for evaluation may be more important than the number of years.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3611
Author(s):  
Sandra Gonzalez-Piedra ◽  
Héctor Hernández-García ◽  
Juan M. Perez-Morales ◽  
Laura Acosta-Domínguez ◽  
Juan-Rodrigo Bastidas-Oyanedel ◽  
...  

In this paper, a study on the feasibility of the treatment of raw cheese whey by anaerobic co-digestion using coffee pulp residues as a co-substrate is presented. It considers raw whey generated in artisanal cheese markers, which is generally not treated, thus causing environmental pollution problems. An experimental design was carried out evaluating the effect of pH and the substrate ratio on methane production at 35 °C (i.e., mesophilic conditions). The interaction of the parameters on the co-substrate degradation and the methane production was analyzed using a response surface analysis. Furthermore, two kinetic models were proposed (first order and modified Gompertz models) to determine the dynamic profiles of methane yield. The results show that co-digestion of the raw whey is favored at pH = 6, reaching a maximum yield of 71.54 mLCH4 gVSrem−1 (31.5% VS removed) for raw cheese whey and coffee pulp ratio of 1 gVSwhey gVSCoffe−1. The proposed kinetic models successfully fit the experimental methane production data, the Gompertz model being the one that showed the best fit. Then, the results show that anaerobic co-digestion can be used to reduce the environmental impact of raw whey. Likewise, the methane obtained can be integrated into the cheese production process, which could contribute to reducing the cost per energy consumption.


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.


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