Effect of ammonium chloride,ammonium sulphate and sodium nitrate on take‐all and grain yield of wheat in southwestern Australia

Five field experiments measured the effect of three sources of nitrogen (N) fertilizer, applied at 45 kg N/ha, on the incidence of take‐all and grain yield of wheat. The N fertilizers were ammonium sulphate, ammonium chloride and sodium nitrate. Compared with the nil N treatment, ammonium nitrogen fertilizer, either as ammonium sulphate (ASdr) or ammonium chloride (ACdr) drilled with the seed, lowered the severity of take‐all. Sodium nitrate topdressed (SNtd) to the soil surface reduced the severity of take‐all in three of the five experiments, while ammonium sulphate topdressed (AStd) reduced the severity in four experiments. Ammonium sulphate and ammonium chloride drilled with the seed were equally effective in reducing the severity of take‐all in three of the five experiments. However, ACdr was more effective than ASdr in reducing the severity of take‐all in one experiment, whereas ASdr was more effective than ACdr in another experiment. In experiments 1 and 5, the reduction in take‐all severity between the ASdr and ACdr treatments did not affect grain yield. Results suggested that grain yield losses from take‐all are most severe where wheat plants are deficient in N. Fertilizers containing chloride are unlikely to control take‐all disease of wheat on soils of southwestern Australia.     

Effect of ammonium chloride,ammonium sulphate,and sodium nitrate on take‐all and grain yield of wheat grown on soils in South‐western Australia

Five field experiments are described which measured the effect of three sources of nitrogen (N) fertilizer, applied at 45 kg N/ha, on the incidence of take‐all and grain yield of wheat. The N fertilizers were ammonium sulphate, ammonium chloride, and sodium nitrate. Compared with the Nil N treatment, ammonium‐nitrogen fertilizer, either as ammonium sulphate (ASdr) or ammonium chloride (ACdr) drilled with the seed, lowered the severity of take‐all. Sodium nitrate topdressed (SNtd) to the soil surface reduced the severity of take‐all in three of five experiments, while ammonium sulphate topdressed (Astd) reduced the severity in four of the five experiments. Ammonium sulphate and ammonium chloride drilled with the seed were equally effective in reducing the severity of take‐all in three of the five experiments. However, ACdr was more effective than ASdr in reducing the severity of take‐all in one experiment whereas ASdr was more effective than ACdr in another experiment. In these two experiments (1 and 5), the effects of the reduction in take‐all severity between the ASdr and ACdr treatments did not affect grain yield. The results suggest that grain yield losses from take‐all are most severe where wheat plants are deficient in N. Chloride containing fertilizers are unlikely to control take‐all disease of wheat on soils of southwestern Australia.     

Effect of seed zinc content on grain yield and zinc concentration of wheat grown in zinc‐deficient calcareous soils

Field experiments were carried out to study the effect of different seed‐zinc (Zn) content on grain yield and grain Zn concentration in a bread wheat cultivar Atay 85 grown in a severely Zn‐deficient soil under rainfed and irrigated conditions for two years. Three groups of seeds with Zn contents of 355, 800, and 1,465 ng Zn seed^‐1 were obtained through different number of foliar applications of ZnSO₄.7H₂O in the previous crop year. Experiments were carried out with 23 kg Zn ha^‐1 (as ZnSO₄.7H₂O) and without Zn fertilization to the soil. Grain yield from seeds with 800 and 1,465 ng Zn seed^‐1 content was significantly higher than that from low seed‐Zn, especially under rainfed conditions. In the first year, under rainfed and Zn‐deficient conditions, yield of plants grown from the highest seed‐Zn content was 116% higher than the yield of plants grown from the low seed‐Zn content. However, in the first year soil‐Zn application combined with low‐Zn seed resulted in a yield increase of 466% compared to nill Zn treatment with low‐Zn seed, indicating that higher seed‐Zn contents could not compensate for the effects of soil Zn application. Soil Zn application significantly increased Zn concentrations in shoot and grain. However, the effect of different seed Zn contents on Zn concentrations of plants was not significant, probably due to the dilution of Zn in tissues resulting from enhanced dry matter production. The results presented show that wheat plants grown from seed with high Zn content can achieve higher grain yields than those grown from the low‐Zn seed when Zn was not applied to the soil. Therefore, sowing seeds with higher Zn contents can be considered a practical solution to alleviate Zn deficiency problem, especially under rainfed conditions in spite of it being insufficient to completely overcome the problem.     

Effect of different zinc application methods on grain yield and zinc concentration in wheat cultivars grown on zinc‐deficient calcareous soils

The effect of six different zinc (Zn) application methods on grain yield and concentrations of Zn in whole shoots and grain was studied in wheat cultivars (Triticum aestivum, L. cvs. Gerek‐79, Dagdas‐94 and Bezostaja‐1 and Triticum durum, Desf. cv. Kunduru‐1149) grown on severely Zn‐deficient calcareous soils (DTPA‐extractable Zn: 0.12 mg‐kg^‐1 soil) of Central Anatolia which is the major wheat growing area of Turkey. Zinc application methods tested were: a) control (no Zn application), b) soil, c) seed, d) leaf, e) soil+leaf, and f) seed+leaf applications. Irrespective of the method, application of Zn significantly increased grain yield in all cultivars. Compared to the control, increases in grain yield were about 260% with soil, soil+leaf, and seed+leaf, 204% with seed and 124% with leaf application of Zn. In a similar manner, biomass production (dry weight of above‐ground parts) was increased by Zn treatments. The highest increase (109%) was obtained with the soil application and the lowest increase (40%) with the leaf application. Significant effects of Zn application methods were also found on the yield components, i.e., spike number.m^‐2, grain number‐spike^‐1, and thousand kernel weight. Spike number.m^‐2 was affected most by Zn applications, particularly by soil and soil+leaf applications. Concentrations of Zn in whole shoots and grain were greatly affected by different Zn treatments. In plants without added Zn, concentrations of Zn were about 10 mg‐kg^‐1 both in shoots and grain and increased to 18 mg‐kg^‐1 dry weight (DW) by soil application of Zn, but not affected by seed application of Zn. Soil+leaf application of Zn had the highest increase in concentration of Zn in shoot (82 mg‐kg^‐1 DW) and grain (38 mg‐kg^‐1 DW). Soil application of Zn was economical and had long‐term effects for enhancing grain yield of wheat grown on Zn deficient soils. When high grain yield and high Zn concentration in grains are desired, soil+leaf application of Zn was most effective method of Zn application.     

Applied phosphorus and potassium effects on yield of dallisgrass‐bermudagrass pastures 1

There are substantial areas of dallisgrass (Paspalum dilatatum Poir.)‐common bermudagrass (Cynodon dactylon (L). Pers.) summer‐type pastures in the Southeastern Central Plain, but little information is available on their response to P and K fertilization. The purpose of this study was to measure the response of dallisgrass‐common bermudagrass pastures to P and K fertilization with and with‐ out N. Phosphorus and K were applied to two soils in May each year for three years. Yield data were collected by clipping a swath through the length of the plots when the minimum forage height was approximately 30 cm. Responses to P and K applications were obtained when the soil test levels were low to very low, but not when they were medium as determined by the Mississippi Soil Test (MST). Forage P concentration of the control in the medium P and K soil was within the adequate range of 2.8 to 3.4 g/kg, but forage K concentration was below the critical range of 16 to 18 g/kg. Forage P and K concentrations of the controls in the low P and K soil were below critical levels. At both locations forage P and K concentrations were increased by P and K fertilization. Available soil P increased with rate of P application but soil extractable K was unaffected by K application. No yield response to P and K are likely at medium soil test levels (MST) even at high rates of N. There was no response to P and K application without N.     

Effect of rock phosphate and superphosphate on crop yield and soil phosphorus test in long‐term fertility plots

Abstract

A long‐term (1968–1987) field study using corn‐soybean in rotation was conducted to compare the effect of rock phosphate (RP) and superphosphate (SP) at two lime levels on crop yield, soil available phosphorus (P) as Bray P‐1 (0.025M HCl + 0.03M NH₄F) and Bray P‐2 (0.1M HCl + 0.03M NH₄F) tests, and on the relationship between crop yield and available P tests. Treatments included a control, application of RP and SP ranging from 12 to 96 kg P₂O₅ ha^‐1 yr^‐1, and combinations of RP with SP or sulphur at various rates. The RP was applied once in 1968 at 8 times the annual rate while SP was applied annually until 1985. Corn and soybean yields increased with P application, more with SP than with RP. Bray P‐l and Bray P‐2 increased linearly with the amount of P applied as SP or RP. A significant correlation (r > 0.64) was found between corn yield and Bray P‐2 at low lime level with both P sources. In contrast, a poor correlation (r < 0.50) was found between soybean yield and soil P tests. Both RP and SP were effective sources of P fertilizers for corn on soils treated with a small amount of lime compared with a large amount of lime. Under low lime the Bray P‐2 accounted for 41% and 66% variability in com yield with applied RP and SP, respectively. On the other hand, Bray P‐1 was only of value when SP was the source of P.     

Effects of phosphorus application method and rate on furrow‐irrigated ridge‐tilled grain sorghum

Conservation tillage systems, including ridge‐tillage, have become increasing popular with producers in the central Great Plains because of their effectiveness in controlling soil erosion and conserving water. A major disadvantage of the ridge system is that nutrient placement options are limited by lack of any primary tillage options. The objective of this research was to investigate the effects of method of phosphorus (P) placement and rate on irrigated grain sorghum [Sorghum bicolor (L.) Moench] grown in a ridge‐tillage system on a soil low in available P. This experiment was conducted from 1993 to 1995 on a producer's field near the North Central Kansas Experiment Field at Scandia, Kansas on a Carr sandy loam soil (course, loamy, mixed, calcareous, mesic, Typic Udifuvents). Treatments consisted of fertilizer application methods, surface broadcast, single band starter (5 cm to the side and 5 cm below seed), dual band starter (one band on each side of the row), and knifed in the center of the row middle (38 cm from each adjacent row). Each of these treatments was made at either 22 or 44 kg P₂O₅ ha^‐1, and nitrogen (N) also was included at the rate of 13 kg ha^‐1. Additional treatments were, a combination of 13 kg N and 44 kg P₂O₅ ha^‐1 applied half broadcast and half as a single band starter, a 1:1 N:P₂O₅ ratio (44 kg N and 44 kg P₂O₅ ha^‐1) applied as a single band starter, and a 3:1 ratio (134 kg N and 44 kg P₂O₅ ha^‐1) applied as a single band starter. A no‐P check plot also was included. Broadcast and center‐of‐row middle knife applications were made approximately 1 week before planting. After planting, N was balanced on all plots to give a total of 180 kg ha^‐1. Applied P treatments improved grain yield and nutrient uptake and consistently shortened the time from emergence to mid‐bloom in all 3 years of the experiment. On this low soil test P soil, treatments that subsurface banded P increased grain yield by 1.27 Mg ha^‐1 compared to broadcast treatments. Placing N and P in a single starter band 5 cm to the side and 5 cm below the seed was as effective as placing a band on each side of the row. Knife applying N and P in the center of the row was not as effective as placement beside the row. Single band starter application of N and P in a 1:1 and or 3:1 N:P₂O₅ ratio consistently increased yields and nutrient uptake and shortened the time to mid‐bloom as compared to the single band starter treatment that provided only 13 kg N ha^‐1. Over the 3 years of the study, these 1:1 and 3:1 N:P₂O₅ ratio starters were clearly superior to an other treatments.     

Influence of split‐applied nitrogen on grain yield and protein content in ten grain sorghum culti‐vars 1

More information on the response of newly developed or introduced grain sorghum cultivare to split‐applied nitrogen (N) in semi‐arid rainfed agriculture is needed. Therefore, the influence of four split‐applied N schedules (100/0, 66/34, 50/50, and 34/66) on six American (SC 283, SC 274, SC 669, B 66181, SC 33, and RTam 428), and four West African (CSm 63, 1S 6704c, 1S 7173c, and 1S 7419c) grain sorghum cultivars was evaluated. The split‐applied N significantly increased grain yield and percent protein in grain sorghum over a one‐time application of N. The increase in yield and protein content varied among varieties and schedules of N application. Varieties SC 574, RTam 428, and Csm 63 at split‐applied schedules of 66/34, 50/50, and 34/66, respectively, gave the highest yield over one‐time application of N. Similar differences in percent protein in grain among cultivars due to split‐applied N were observed.     

The effect of subsurface aluminium on the growth and uptake of surface‐applied phosphorus by wheat seedlings 1

Seedlings of four cultivars of wheat (Triticum aestivum L.) differing in tolerance to aluminium (Al) were grown for 14 to 20 days using a split‐root sand/solution culture technique. Each culture tube was divided horizontally into two compartments by a root‐permeable paraffin wax barrier, so that phosphorus (P) and aluminium (Al) supply could be varied in the upper 0–80 mm (surface) and lower 80–180 mm (subsurface) compartments, respectively.

Root growth into the subsurface zone was enhanced by increased P supply to surface roots, but only in the absence of subsurface Al. Where subsurface Al was present, increased P supply to surface roots had no effect on the penetration of roots into the subsurface zone. Tolerance to Al in the cultivars used was therefore not related to the ability to translocate P to sites of Al injury.     

Manganese seed content and take‐all of cereals 1

Manganese (Mn) is a critical regulator of many physiological defense reactions of plants to disease; and the severity of take‐all root, crown, and foot rot of cereals has been correlated with such cultural practices as form of nitrogen (N), pH adjustment, and crop rotation which all influence the availability of Mn. This study was initiated to determine if the content of Mn in seed influences the severity of take‐all. Five cultivars of soft red winter wheat (Triticum aestivum L.) were grown under two widely different ecological conditions (alkaline, low Mn soil and Mn sufficient soil) to modify their Mn seed content Four cultivars (Cardinal, Lincoln, Steele, and Twain) differed by 10 to 18 μg g^‐1 in Mn seed content (0.33 to 60 ug seed^‐1) while the Mn seed content of one cultivar (Caldwell) was similar from both locations. All cultivars were grown at three field locations in Indiana with natural infestations of Gaeumannomyces graminis var. tritici (Ggt). Under these moderately‐severe to severe disease conditions, plants from seed with the higher Mn seed content were generally more vigorous, had an average of 11% less take‐all (white heads), and yielded an average of 165 kg/ha more grain than plants from seed of the same cultivar with a lower Mn content No significant differences in vigor, yield, or take‐all severity were observed with either source of the cultivar grown from seed produced under widely different environments unless there was a significant difference in Mn seed content.     

Comparison of wheat yield under uniform and variable rates of fertilizer on spatially‐eroded land

Abstract

Field studies were made to determine the yield and quality of wheat at different landscape positions managed with uniform vs. variable rates of nitrogen (N). A moderately‐eroded wheat farm near Thana (Swat) was divided into four parallel transects which were further divided into two strips each. On one strip, fertilizer was applied at a uniform rate of 120 kg N ha^‐1, and along the other strip, three different rates of N (80, 110, and 125 kg N ha^‐1) were applied to match the crop productivity patterns. A basal dose of 90 kg P₂O₅ and 60 kg K₂O ha^‐1 was applied to the whole field. Soil profiles were described for the three different zones, i.e., low, medium, and high productivity zones. Soil in Zone I was Pirsabak, moderately deep variant, and in Zones II and III, Badwan soil series. Although uniformly fertilized strip (120 kg N ha^‐1) received 40 and 10 kg N ha¹ more than Zone I and Zone II (variable management strategy), there were no significant differences in yield. The differences in three fertilizer management zones were due to differences in moisture content at sowing, infiltration rate, lime content, steepness, and soil depth. Test weight of wheat grains was not significantly affected. Protein content of wheat was significantly higher in variably fertilized strips than in uniformly treated strips. Based on these results, it is suggested that farms with spatially‐variable soils should be fertilized according to the crop productivity and soil fertility patterns.     

Effects of normal and Fe‐treated organic matter on Fe chlorosis and yields of grain sorghum

Abstract

A greenhouse study was conducted to evaluate the effects of normal and Fe‐treated plant material on Fe chlorosis and yields of grain sorghum. Pigweed, guar, clover, sunflower and wheat plants grown in the field for six weeks were sprayed with a 20% ferrous sulfate solution. The plants were harvested after 48 hours, air dried, then ground to pass through a 0.5 mm stainless steel seive. Different rates of normal and Fe‐treated plant material (0, 14.8, 22.2 and 29.6 Mg ha^‐1) were added to the Pernitas fsl (Typic Agiustoll).

Chlorosis increased with increasing rates of normal plant material added to the soil. Conversely, applications of Fetreated plant material reduced Fe deficiency chlorosis in grain sorghum. The order of effectiveness of Fe‐treated plant material was: sunflower > pigweed > guar > clover > wheat. There was no significant growth response to the untreated plant material. Growth responses to the Fe‐treated plant material were: sunflower > pigweed > guar > wheat > clover. Data obtained indicate that sunflower and pigweed are good Fe‐carriers and could be used to recycle Fe in the soil to correct Fe deficiency chlorosis and increase yields     

Effect of sewage sludge–coir pith pellets on dry matter yield and trace metal concentration in various plant parts of forage maize

Sewage sludge (SS), a highly heterogeneous semisolid fraction of sewage water (about 1% of the sewage water), contains various amounts of nitrogen (N) and phosphorus (P) as well as trace elements such as cadmium (Cd), lead (Pb), copper (Cu), nickel (Ni) and zinc (Zn) with extremely variable physical and chemical compositions. Application of SS improves soil properties, increases yield and simultaneously increases trace metal content in soil and plants. The difficulty in handling, transporting and applying SS and its adverse effect, especially trace metal content in soil and plant, can be overcome by SS–coir pith pelletization (SSCP) or mixing with sewage sledge–coir pith mixture (SSCM). A study was undertaken to evaluate the prepared SSCM and SSCP (1:1 ratio of SS and coir pith) along with SS on dry matter yield, trace metal content in soil and plant parts. The results showed that increased rates of application of SS or SSCM or SSCP increased the green and dry fodder yield of forage maize. Application of SS as either SSCM or SSCP at 1.2 and 2.4 g pot^?1 significantly reduced the trace metal content diethylene triamine pentaacetic acid (DTPA extractable) in soil and plant parts (leaves steam and root) compared to SS application. Therefore, in order to reduce the bioavailability of trace metal in soil and its uptake by plant, application of SSCM or SSCP at 1.2 or 2.4 g pot^?1 proved to be a better option than SS application.     

Variation of plant‐test phosphorus for individual lupin and wheat tops

Abstract

Two field experiments measured variation of phosphorus (P) concentration in dried tops (plant‐test P) of individual lupin (Lupinus angustifolius cv. Merrit) and wheat (Triticum aestivum cv. Cadoux) plants collected from random locations in experimental plots treated with different levels of superphosphate. Plant‐test P for the individual tops varied by between 4 to 65% of mean values. Coefficient of variation for the 10 individual plants per plot varied from 10 to 24%. For each plot, mean plant‐test P for the 10 individual tops were similar to values for bulk samples of 30 plants collected at random within the plot. It is concluded that a bulk sample of 30 lupin or wheat plant tops need to be collected from uniform areas in farmer paddocks to provide a representative estimated of the current P status of the crop.     

Yield of take‐all infested winter wheat as influenced by inhibiting nitrification with dicyandiamide

Abstract

The potential for using dicyandiamide (DCD) to enhance yield of take‐all‐infested winter wheat (Triticum aestivum L.) was evaluated in six field experiments on four acid soils (pH 5.7–6.2). Ammonium and NO₃ ^‐ concentrations and NH₄ ⁺: NO₃ ^‐ ratios in 0–10 and 10–20 cm soil depths were measured for ten weeks after spring topdressing 180 kg N/ha as urea with 0, 13, or 27 kg DCD/ha. Nitrification was strongly inhibited for 6 to 10 weeks by either 13 or 27 kg DCD/ha. Averaged over the ten‐week sampling period, NH₄ ⁺: N0₃ ^‐ ratios in the 0–10 cm depth of soil were 36: 1 for DCD‐treated plots as compared to 2: 1 for plots receiving only urea. Ratios in DCD‐treated plots were considerably wider than ratios associated with take‐all suppression (10: 1 to 3: 1) in earlier studies. Extractable NH₄ ⁺ + NO₃ ^‐ concentrations in soil were high in DCD‐treated plots after 30 to 40 days, suggested that DCD had reduced crop uptake of N because of the lower mobility of NH₄ ⁺ as compared to NO₃ ^‐. In four of the six studies, grain yields tended to be reduced by DCD. Results suggest that lower rates of DCD and/or application of some NO₃ ^‐ will be necessary if DCD is to be used as a tool for suppressing take‐all.     

Influence of chloride on the uptake and trans‐location of phosphorus in potato

Both chloride (Cl) and sulphate (SO₄) were found to impair the uptake of phosphorus (H2³²PO₄) through the roots of potato in a hydroponically conducted experiment. Radioactive phosphorus (³²P) was used as the marker. The presence of either Cl and SO₄ alone in the nutrient solution made no difference on the impairment. Both ions also inhibited the long‐distance transport of P from roots to shoots. The inhibition by Cl was much greater than that by SO₄, and increased with the concentration of Cl rising from 0 to 15.5 mM in solution.     

Yield and phosphorus efficiency of some lowland rice varieties at different levels of soil‐available phosphorus

Abstract

A field experiment was conducted on an Aerie Haplaquept soil to study the effect of phosphorus (P) deficiency in soil on the P nutrition and yield of five modern varieties of rice, viz., Purbachi, BR1, BR3, BR14, and BR29, popular with the rice farmers of Bangladesh. Soil‐available P in the different plots of the experimental field varied widely, from 2.8 to 16.4 ppm. This plot to plot variation in soil‐available P content resulted from differences in the total amounts (0 to 480 kg ha^‐1) of P the plots had received over a period of 8 years in a long‐term P fertilizer trial conducted previously in the same field. Phosphorus deficiency in soil drastically reduced the grain yield of all the rice varieties. In severely P deficient plots, where soil‐available P was around 3 ppm, the yield was less than 1 ton ha^‐1 while in plots containing an adequate P level, i.e., >6 ppm, the yield was more than 41 ha^‐1. Rice yield increased linearly with an increase in soil P content up to 6 ppm, and the highest grain yield for any variety, obtained at 6–7 ppm of soil‐available P leveled off at this point. Soil P deficiency not only decreased rice yield severely but also decreased P content in straw and grain drastically. However, differences among rice varieties were noted in P nutrition, particularly at low soil P levels. The rice varieties differed markedly also in respect of internal P efficiency. The BR29 showed the highest internal P efficiency both at low and high soil P levels. In all the rice varieties, internal P efficiency decreased with an increase in soil P levels.     

Decreased capacity of take‐all fungus to oxidize manganous ions is associated with take‐all decline

The phenomenon of decline of take‐all [a disease on wheat caused by Gaeumannomyces graminis var. tritici (Ggt)] is poorly understood. In this study, the capacity of Ggt strains, isolated from wheat roots grown in the field plots exhibiting various levels of take‐all decline, to oxidize Mn²⁺ ions was tested. Growth of all Ggt isolates on agar was increased by an addition of up to 100 mg'L^‐1 Mn²⁺ and was decreased by greater concentrations. The Ggt isolates oxidized Mn²⁺ to Mn³⁺ and/or Mn⁴⁺. There was a negative relationship (r=‐0.69) between the Mn²⁺ oxidation ranking and the extent of take‐all decline. A decreased capacity to oxidize Mn²⁺ causes a decrease in Ggt virulence and may result in decline in take‐all. This mechanism of take‐all decline is expected to act additively with other factors.     

Effect of dry‐heat sterilization on chemical properties of Puerto Rican soils

Abstract

Few references explain the effects of dry‐heat sterilization on soil chemical properties. Yet dry heating at 121°C for 2 hours is the prescribed USDA Animal, Plant, and Health Inspection Service basic treatment for soils entering United States ports of entry. This study concerns the effects of air drying and dryheat sterilization on chemical properties of Puerto Rican soils, chiefly macronutrients and micronutrients, found after extracting with Mehlich‐1 and Olsen solutions. Results for dry heating are compared with reported results for other sterilization procedures.

Dry heating did not significantly alter soil N, organic matter content, or soil bases. Depending on the extractant used, changes in P concentrations were significant. Results for micronutrient determinations were more variable and also depended on the extractant used after sterilization. Concentrations of Mn and Fe extracted from dry‐heated soils were significantly greater than concentrations extracted from air‐dried soils.

Effects of dry‐heat sterilization on soil chemical properties generally followed results published elsewhere for steaming, exceptions depending on the extractant used. Published results from chemical sterilization established methylbromide as being closest to dry heat results.