Frequency, depth and rate of phosphorus fertilizer application effects on alfalfa seed yields

2014 ◽  
Vol 94 (7) ◽  
pp. 1149-1156 ◽  
Author(s):  
Tiejun Zhang ◽  
Junmei Kang ◽  
Zhongxiang Zhao ◽  
Wenshan Guo ◽  
Qingchuan Yang

Zhang, T., Kang, J., Zhao, Z., Guo, W. and Yang, Q. 2014. Frequency, depth and rate of phosphorus fertilizer application effects on alfalfa seed yields. Can. J. Plant Sci. 94: 1149–1156. Efficient phosphorus (P) management is important for alfalfa (Medicago sativa L.) seed production and is necessary in order to alleviate the negative environmental effects of excess P application. The study was conducted on both very low-P and optimum-P soils to evaluate the effects of two frequencies (annual and triennial applications), two depths (7–8 and 15–16 cm), and three rates (15, 30, and 45 kg P ha−1) of P fertilization on seed yield, total P uptake (TPU), P-use efficiency of applied P (PUE), and recovery of P fertilizer (PR). There was a zero-P control. Under the model of annual application, the highest seed yields were obtained with the rates of 30 or 45 kg P ha−1. Under the model of triennial application, however, the seed yield decreased linearly with increasing rates in the first year. Averaged across frequency and depth, PUE and PR decreased linearly but TPU increased linearly with increasing P application rate. Triennial application of 45 kg of P led to higher mean seed yield than annual application of 15 kg of P, and its PUE and PR values were higher than triennial application of 90 and 135 kg of P. However, on low-P or optimum-P soil, annual application of 30 or 45 kg of P resulted in the highest mean seed yields compared with low PUE and PR. Thus, triennial application of a low P rate leads to a high alfalfa seed yield and has potential economic and environmental benefits.

2008 ◽  
Vol 15 (4) ◽  
pp. 423 ◽  
Author(s):  
I. SAARELA ◽  
H. HUHTA ◽  
P. VIRKAJÄRVI

In order to update fertilisation recommendations for Finnish silty and sandy soils, the effects of repeated phosphorus (P) fertilisation on the yields of cereals, grasses and other crops were measured at ten sites for 9 to 18 years. Results of some earlier studies were also used in examining the relationships of the yield responses to applied P and to the soil test values measured by the Finnish ammonium acetate method (PAc). Significant effects of P fertilisation were observed at all sites that had low or medium PAc values; in the case of potatoes, even at sites with fairly high values. The mean relative yield without applied P divided by yield with 60 or 45 kg P ha-1 of the ten sites was 81% (mean PAc 11.6 mg dm-3) varying from 55% at the PAc value of 4.7 mg dm-3 to 100% at the highest PAc values. In order to achieve a relative yield of 97%, which is considered the optimum for cereals and leys, the required mean annual application of P in the later parts of the experiments was 25 kg ha-1 (variation 0-42 kg ha-1). On the six soils that had low or medium PAc values (4.5-9.1 mg dm-3, mean 8.0 mg dm-3), relative yield was 97% at the P application rate of 35 kg ha-1 (variation 22-42 kg ha-1), while 11 kg P ha-1 (variation 0-25 kg ha-1) sufficed on the four soils that had higher PAc values (mean 20.8 mg dm-3, variation 11.7-35.2 mg dm-3). Reasons for the poor availability of P in silty and sandy soils were discussed.;


2003 ◽  
Vol 83 (1) ◽  
pp. 189-197 ◽  
Author(s):  
W. E. May ◽  
H. A. Loeppky ◽  
D. C. Murrell ◽  
C. D. Myhre ◽  
J. J. Soroka

Preharvest applications of glyphosate have been shown to be effective in controlling Canada thistle in annual crops, but may reduce alfalfa seed yield depending on time and rate of application. The objective of this study was to determine the effect of preharvest applications of glyphosate on subsequent alfalfa seed yield and quality. The effects of timing, 1, 26, 51 and 76% alfalfa seed pod maturity, and rate, 0, 440, 880, 1320, and 1760 g a.i. ha-1, of a preharvest application of glyphosate on alfalfa seed yield and quality in the year of application, and regrowth and seed yield in the following year were determined. The rate of glyphosate applied did not affect seed yield in the application year; however, in the following year, growth and seed yield were reduced as rates increased. Delaying the application of glyphosate increased seed yields in the application year, but decreased alfalfa regrowth and flowering the following year. Germination and seedling emergence were not affected by the rate or timing of the glyphosate. A preharvest application of glyphosate at 1760 g a.i. ha-1 at 76% pod maturity is a viable option in the last year of seed production. Key words: Alfalfa (Medicago sativa L.), glyphosate, abnormal seeds, seed quality, and seedling vigour


2021 ◽  
Vol 31 (1) ◽  
pp. 45-50
Author(s):  
A. T. Omokanye ◽  
J. T. Amodu ◽  
S. O. Onifade

Forage, seed yields and herbage chemical composition of phasey bean Macroptilium lathyroides) were investigated at 3 intra-row plant spacings (15, 30 and 45cm between plants; 50 cm between roms), 4 phosphorus (P) fertilizer application rates (O), 50, 100 and 750 kg/ha P) and 5 harvest stages (uncut control, 6, 9, 12 and 15 weeks post sowing) in two growing seasons at Shika in northern Nigeria. The least intra-row plant spacing (15cm) produced higher (p<0.01) total DM vield (1.50 t/ha) than wider spacings. The proportion of leaf was least (40 %) in the widest spacing compared with other spacings (59-62 %). The P-fertilized plots produced 58-60% more total DM vields than the unfertilized plots and total DM yields increased with advanced plant growth. The highest percentage (61-63) of leaf was recorded from 6 to 12 weeks post sowing. Nitrogen level in herbage increased (p<0.05) with increased intra-row plant spacing and P application. Phosphorus and Calcium. Levels in herbage did not respond to intra-row plant spacing but increased with P application. The Ca:P ratios at the harvest stages were between 1:1 and 6:1. The highest seed yields (198 and 188 kg/ha) were recorded respectiely in the least intra-row plant spacing and the application of 100 kg Piha. Supplementation of calves on grasses/cereal stovers with phasey bean hay in a sustainable crop livestock production systems is suggested.


2019 ◽  
Vol 11 (17) ◽  
pp. 4799
Author(s):  
Wenting Jiang ◽  
Xiaohu Liu ◽  
Xiukang Wang ◽  
Lihui Yang ◽  
Yuan Yin

Optimizing the phosphorus (P) application rate can increase grain yield while reducing both cost and environmental impact. However, optimal P rates vary substantially when different targets such as maximum yield or maximum economic benefit are considered. The present study used field experiment conducted at 36 experiments sites for maize to determine the impact of P application levels on grain yield, plant P uptake, and P agronomy efficiency (AEP), P-derived yield benefits and private profitability, and to evaluated the agronomically (AOPR), privately (POPR), and economically (EOPR) optimal P rate at a regional scale. Four treatments were compared: No P fertilizer (P0); P rate of 45–60 kg ha−1 (LP); P rate of 90–120 kg ha−1 (MP); P rate of 135–180 kg ha−1 (HP). P application more effectively increased grain yield, reaching a peak at MP treatment. The plant P uptake in HP treatment was 37.4% higher than that in P0. The relationship between P uptake by plants (y) and P application rate (x) can be described by the equation y = −0.0003x2 + 0.1266x + 31.1 (R2 = 0.309, p < 0.01). Furthermore, grain yield (y) and plant P uptake (x) across all treatments also showed a significant polynomial function (R2 = 0.787–0.846). The MP treatment led to highest improvements in P agronomic efficiency (AEP), P-derived yield benefits (BY) and private profitability (BP) compared with those in other treatments. In addition, the average agronomically (AOPR), privately (POPR), and economically optimal P rate (EOPR) in 36 experimental sites were suggested as 127.9 kg ha−1, 110.8 kg ha−1, and 114.4 kg ha−1, which ranged from 80.6 to 211.3 kg ha−1, 78.2 to 181.8 kg ha−1, and 82.6 to 151.6 kg ha−1, respectively. Economically optimal P application (EOPR) can be recommended, because EOPR significantly reduced P application compared with AOPR, and average economically optimal yield was slightly higher compared with the average yield in the MP treatment. This study was conducive in providing a more productive, use-effective, profitable, environment-friendly P fertilizer management strategy for supporting maximized production potential and environment sustainable development.


1991 ◽  
Vol 71 (2) ◽  
pp. 481-489 ◽  
Author(s):  
J. R. Moyer ◽  
R. W. Richards ◽  
G. B. Schaalje

Alfalfa was seeded in row spacings of 36, 72 and 108 cm and at broadcast seeding rates of 0.33, 1.0 and 3.0 kg ha−1 on irrigated land at Tilley (1983) and Lethbridge (1984), Alberta to determine the effect of plant density on weed growth and alfalfa seed yield. During the seed-producing years at each location, herbicide treatments were overlaid on seeding treatments in a split-block arrangement to assess the joint effect of herbicides and plant density on alfalfa seed yield. Hexazinone was the main herbicide used for weed control. Alfalfa seed and weeds were harvested for 5 yr following alfalfa establishment. Alfalfa seed yields tended to be maximum with 36-cm row spacings or the 3.0 kg ha−1 broadcast seeding rate, and were similar in row-seeded and broadcast-seeded alfalfa. Dry matter yields of weeds decreased as row spacings decreased or the broadcast seeding rate increased. Hexazinone controlled quackgrass, sow thistle, flixweed and kochia. In the experiment at Tilley with perennial weed infestations, mean alfalfa seed yields from 1984 to 1985 were 20% larger when herbicides were used than in the untreated check. Alfalfa plant densities slightly larger than currently recommended usually produced the largest seed yields and smallest weed infestations. Key words: Medicago sativa, quackgrass, kochia, sow thistle, flixweed, hexazinone


2002 ◽  
Vol 94 (6) ◽  
pp. 1393-1399 ◽  
Author(s):  
Nathan A. Slaton ◽  
Charles E. Wilson ◽  
Richard J. Norman ◽  
Sixte Ntamatungiro ◽  
Donna L. Frizzell

1996 ◽  
Vol 76 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage


Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 164-167 ◽  
Author(s):  
J. Waddington

Applications of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 1.1 kg/ha at the start of each growing season severely damaged established alfalfa (Medicago sativaL. ‘Beaver’) and reduced seed yield 32% over a 4-yr period. Dandelion (Taraxacum officinaleWeber) populations were reduced but perennial sowthistle (Sonchus arvensisL.) increased in frequency. Dichlobenil (2,6-dichlorobenzonitrile) applied at 2.1 kg/ha controlled both dandelion and perennial sowthistle. Alfalfa was damaged initially but rapid recovery resulted in an increase in seed yield in 2 yr out of 4. Terbacil (3-tert-butyl-5-chloro-6-methyluracil) applied at 1.1 kg/ha also controlled dandelion and perennial sowthistle. No alfalfa damage was evident and seed yields were increased 34% over a 3-yr period. Seed yield increased 30% where asulam (methyl sulfanilylcarbamate) was applied at 4.5 kg/ha, but there was no visible effect on the growth of either alfalfa or weeds. Simazine [2-chloro-4,6-bis (ethylamino)-s-triazine], propham (isopropyl carbanilate) + PCMC (p-chlorophenyl-N-methyl carbamate), pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide], and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], did not affect alfalfa seed production significantly, although simazine and diuron did reduce dandelion populations.


1991 ◽  
Vol 42 (7) ◽  
pp. 1271 ◽  
Author(s):  
GJ Blair ◽  
DC Godwin

Lack of data on root growth and relationships between root parameters and P uptake are major limitations to understanding and modelling P efficiency in crop and forage plants. An experiment was conducted whereby two accessions of white clover (Trifolium repens, Chiswick and Ladino) were grown in pots in a P deficient soil fertilized with a low (P5 [kg ha-1]) or high (P40) P application rate. Plants were harvested at 10, 16, 22, 28, 34 and 40 days after transplanting and tops harvested and roots recovered from the pots. Detailed measures of root members were made at 10, 16 and 22 days and these correlated with P uptake. Dry weight of tops of accessions was the same between the two rates of P until day 28. At 40 days, the tops yield of Ladino was higher than Chiswick at P40. Root dry weight increased with increasing P application rate and time from day 16 onwards. Significant differences in root growth only occurred at the 16 and 34 day harvests at P5. Ladino tended to have a greater mean P uptake over time than did Chiswick at both P levels. P uptake was found to be positively correlated with shoot and root dry weight, root length, root number, root volume and surface area, and negatively correlated with mean root diameter and mean length per root. Root extension rate at low P in Ladino was greater than that in Chiswick, which may explain the greater P uptake by Ladino at low P at later harvests in this experiment. The changes in length, diameter and number of roots in the two accessions examined in this study, with time, in response to P, reflect some form of coordination. Chiswick tended to produce many short roots whilst Ladino fewer long roots. Only small differences in P uptake per unit root length were measured, which suggest that total root length or root extension rate is the primary determinant of total P uptake in these accessions of white clover.


Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 264
Author(s):  
Ahmed Jasim ◽  
Lakesh K. Sharma ◽  
Ahmed Zaeen ◽  
Sukhwinder K. Bali ◽  
Aaron Buzza ◽  
...  

Phosphorus (P) is an element that is potatoes require in large amounts. Soil pH is a crucial factor impacting phosphorus availability in potato production. This study was conducted to evaluate the influence of P application rates on the P efficiency for tuber yield, specific gravity, and P uptake. Additionally, the relationship between soil pH and total potato tuber yield was determined. Six rates of P fertilization (0–280 kg P ha−1) were applied at twelve different sites across Northern Maine. Yield parameters were not responsive to P application rates. However, regression analysis showed that soil pH was significantly correlated with total potato tuber yield(R2 = 0.38). Sites with soil pH values < 6 had total tuber yields, marketable tuber yields, tuber numbers per plant, and total tuber mean weights that were all higher than these same parameters at sites with soil pH ≥ 6. All sites with soil pH< 6 showed a highly correlated relationship between P uptake and petiole dry weight (R2 = 0.76). The P application rate of 56 kg P ha−1 was the best at sites with a soil pH < 6, but 0–56 kg P ha−1 was the best at sites with soil pH ≥ 6.


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