Effect of Low‐Rate Commercial Humic Acid on Phosphorus Availability,Micronutrient Uptake,and Spring Wheat Yield

Abstract

A greenhouse study was conducted to determine the effects of low‐rate commercial humic acid (HA) on phosphorus (P), iron (Fe), and zinc (Zn) availability and spring wheat yields, in both a calcareous soil and a noncalcareous soil. In Phase I, soluble P concentrations were monitored at 1.9, 3.8, and 5.7 cm from a monoammonium phosphate (MAP) fertilizer band that had either been coated with one of two HA products at the equivalent of 1.7 kg HA ha^?1, a label rate, or left uncoated. Sampling occurred periodically up to 48 d after fertilizer application. In Phase II, uptake of P, Fe, and Zn and grain yield were measured in soils that had been fertilized with 7.5 or 25 kg P ha^?1, either coated with HA or left uncoated. In Phase I, only three significant differences (P=0.05) out of 66 comparisons were found in soluble P concentrations between HA and control treatments at time points ranging from 4 to 48 d after fertilization. In addition, no significant differences were found in nutrient uptake, shoot biomass, or grain yield between HA and control treatments. These greenhouse results suggest that low commercial HA rates (～1.7 kg HA ha^?1) may be insufficient to enhance spring wheat growth.     

Boron Nutrition Studies with Cotton and Sunflower in Southern Turkey

Wide variations in boron (B) contents are typical of Turkish soils and plants, and most of the variation, 84% of the plant-soil B values are within the “normal.” Boron application on low B soils can make a contribution to yield in cotton and sunflower crops. Field experiments were carried out on clayey and medium-textured soils, which are Chromoxererts, Haploxererts, Xerochrepts, and Xerofluvents in Southern Turkey to study the effects of boron fertilization on irrigated cotton and rainfed sunflower growth, yield, and yield components. Four levels of boron—0, 1, 2, and 3 kg ha^?1—were applied at planting and the experimental design was completely randomized block design with four replications. There was a 31% and 31.9% increase in seedcotton yield at 3 kg and 2 kg ha^?1 of B, compared to the control only two out of four sites. There was an average increase of 61.4% in boll weight with 2 kg B ha^?1 application compared to the control. Effect of different application rates of B was not significant for fiber length, fiber strength, and fiber length uniformity. All levels of boron produced higher head diameters over control only one out of four sites. Boron applied at the level of 3 kg ha^?1 produced the highest 1000 seed weight of 47.5 g representing an 18% increase over the control. Boron applied at the level of 1 kg ha^?1 produced the highest seed yield, representing a 25% increase over the control only at one out of four sites. Boron was no value as a fertilizer for sunflower under given experimental conditions even though some uptake of boron was occurred. Boron fertilization may be regarded as effective in improving cotton yields.     

Boron Fertilization and Evaluation of Four Soil Extractants: Russet Burbank Potato

Yield‐response correlations with old and improved soil extraction methods for boron (B) are needed. Russet Burbank potato (Solanum tuberosum L.) was grown with two, four, and six B treatments applied in 2004, 2005, and 2006, respectively. Zero and 1.1, 2.2, or 3.4 kg B ha^?1 soil and 0.22 or 0.28 kg B ha^?1 foliar treatments were applied. Boron fertilization did not significantly increase tuber yield or quality despite initially low hot‐water‐extractable B (0.34–0.50 mg kg^?1), although postseason B for unfertilized treatments increased (0.51–0.57 mg kg^?1). Soil‐applied B generally reflected B application relative to the untreated control and the low foliar rates in all three years for the four soil extractions utilized [hot water, pressurized hot water, diethylenetriaminepentaacetic acid (DTPA)–sorbitol, and Mehlich III]. Boron content of potato petiole did reflect application of B in 2 years, but tuber and peel tissues did not consistently reflect application of B.     

Nutrition and Production of Phaseolus vulgaris (BRS estilo) Following Boron Application on Soil

Boron (B) application is an important strategy in highly productive systems, since this micronutrient is involved in amide syntheses, which is related to the grain yield. In this way, the aim of this work was to evaluate the B fertilization effect in nutrition and production of common beans. The experiment was carried out under greenhouse condition, in an entirely randomized design, with five B doses (0, 1, 2, 4, and 6 kg ha^?1) and four repetitions. The relative chlorophyll index, dry mass production, level and accumulation of B were measured. Boron levels in leaves of common beans are linearly enhanced after application of increasing B doses. When B level in soil is low (<0.5 mg kg^?1), boron doses lower than 4.9 kg ha^?1 increase dry mass production, with the highest production observed at a dose of 4.8 kg ha^?1, promoting a 56% in dry mass production compared with control.     

Scaling-up of boron sources for yield and quality of large seeded peanut cultivars under varied agro-ecological conditions in India

Boron (B) deficiency is a common factor in light-textured soils causing poor pod filling and yield in large seeded peanut. Field trials were conducted in soils having 0.20–0.45 mg kg^?1 available B to find out the effectiveness of commercial-grade B sources in large seeded peanuts. B application induced early flowering, increased pods, yield and yield attributes, shelling and 100-seed weight. Soil application of 2.0 kg B ha^?1 as commercial-grade Agricol, Solubor and Borosol increased these parameters to a similar degree as obtained by borax, but were superior over their foliar applications. Similarly, the responses of foliar applications of 1.0 kg B ha^?1 as Chemiebor, Solubor and Borosol were more effective in humid areas. However, foliar applications led to scorching of peanut leaves during dry weather. Thus, soil application of 2.0 kg B ha^?1 is essential to enhance productivity and pod filling in large seeded peanut.     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

Influence of boron fertilization on cauliflower productivity,nutrient uptake and soil nutrient status in an acid Alfisol in Northwestern Himalaya

ABSTRACT

Modern agriculture over the years has resulted in depletion of boron (B) from soil which has been emerged as a serious obstacle for sustainable agriculture. We studied the availability of B in soil and cauliflower (Brassica oleracea var. botrytis L.) productivity under different levels of B fertilization. A field experiment was conducted during 2013–2014 and 2014–2015, at experimental farm of Himachal Pradesh Agricultural University, Palampur on silt-clay loam soil (acid Alfisol) under mid hill wet temperate condition. Different levels of B for the study included 0, 0.75, 1.5, 2.5, 5, 10, 20 and 30 kg B ha^?1 along with recommended dose (RD) of NPK and farmyard manure (FYM, 20 t ha^?1). The application of B influenced biological yield significantly up to 5 kg ha^?1. Highest curd yield in 2013–2014 (11.03 t ha^?1) and 2014–2015 (12.93 t ha^?1) was recorded in 1.5 and 0.75 kg ha^?1 B along with NPK + FYM, respectively. At higher rates of boron i.e. 10, 20 and 30 kg ha^?1, due to toxic effects, a reduction in curd yield was recorded in both years. Maximum mean uptake of N, P and K by leaves and curd was recorded with the application of boron at 1.5 kg ha^?1, whereas mean B uptake was highest when boron was applied at 2.5 kg ha^?1. The highest mean value (1.79 mg kg^?1) of soil available boron was recorded with 30 kg B ha^?1. Application of boron at 2.4 kg ha^?1 was worked out as optimum dose for cauliflower.     

BORON NUTRITION OF PEANUT GROWN IN BORON-DEFICIENT CALCAREOUS SOILS: GENOTYPIC VARIATION AND PROPOSED DIAGNOSTIC CRITERIA

Field studies were conducted to assess boron (B) requirement, critical concentrations in diagnostic parts based on yield response curves and genotypic variation by growing three peanut (Arachis hypogaea L.) cultivars (‘Golden’, ‘BARD-479’, ‘BARI-2000’) on two B-deficient calcareous soils. Boron application significantly increased pod yield of all the cultivars over control. Maximum pod yield increases were: ‘Golden’, 16?23%; ‘BARD-479’, 21?27%; and ‘BARI-2000’, 25?31%. The cultivars varied in B efficiency and cv. ‘Golden’ was the most B efficient (81?86%) while cv. ‘BARI-2000’ was the least efficient (76?80%). Boron requirements for near-maximum (95%) dry pod yield were 0.65 kg ha^?1 for ‘Golden’, 0.75 kg ha^?1 for BARD-479 and 0.80 kg ha^?1 for BARI-2000. Critical B concentrations in shoots and seeds were: ‘Golden’, 33 mg kg^?1 and 26 mg kg^?1; ‘BARD-479’, 38 mg kg^?1 and 31 mg kg^?1; and ‘BARI-2000’, 42 mg kg^?1 and 33 mg kg^?1.     

Response of Sunflower to Sulfur Rate and Time of Application under Two Tillage Systems in a Silty Clay Soil of Dera Ismail Khan Pakistan

ABSTRACT

Sulfur (S) availability is a characteristic of conservation tillage. We studied the effects of S on sunflower yield and fatty acid profile under conventional and conservation tillage in silty clay soil of D.I. Khan, Pakistan. Conventional tillage consisted of disk plowing followed by tiller and rotavator, while conservation tillage comprises tiller and disc harrowing. Treatments comprise six sulfur levels (S₁ = 0, S₂ = 20 kg S ha^?1 at sowing, S₃ = 10 kg S ha^?1 at sowing +10 kg S ha^?1 25 days after sowing (DAS), S₄ = 40 kg S ha^?1 at sowing, S₅ = 20 kg S ha^?1 at sowing + 20 kg S ha^?1 25 DAS, and S₆ = 20 kg S ha^?1 at sowing + 10 kg S ha^?1 25 DAS + 10 kg S ha^?1 50 DAS) replicated thrice. After 2 years of experimentation, soil samples were collected (from 0 to 0.30 m depth) for organic matter (OM), total soil N (TSN), and available sulfur analysis. Conservation tillage significantly increased OM, TSN, and S contents in 0–0.30 m soil compared to conventional tillage. Likewise, sunflower plants showed higher achene yield, better fatty acid profile, and net economic returns in conservation tillage than in conventional tillage. Application of 20 kg S ha^?1 at sowing and 10 kg S ha^?1 at each 25 and 50 DAS recorded significantly higher achene yield, higher oil, and linoleic acid contents; however, oleic and oleic/linoleic ratio did not increase with higher S rates. Conservation tillage was effective in increasing OM, TSN, and available S besides increasing yield and economics in silty clay soil.     

Balanced fertilization and bioregulators: enhancing productivity and profitability of wheat (Triticum aestivum)

A field experiment was conducted during the winter seasons between 2004 and 2006 to assess the role of balanced fertilization and bioregulators (foliar-applied brassinosteroid 0.5 mg I^?1, thiourea 1000 mg I^?1 and kinetin 10 mg I^?1) in enhancing the productivity of wheat. Conjoint application of NPKSZn (120 kg N, 40 kg P₂O₅, 30 kg K₂O, 40 kg S, 5.5 kg Zn ha^?1) recorded maximum improvements in yield attributes and significantly out-yielded all the fertilization treatments with 14.90, 4.97 and 6.39% increments in grain yield compared with NPK, NPKS and NPKZn treatments, respectively. Nutrient (N, P, K, S, Zn) content and uptake were also improved significantly with balanced fertilization. Among the bioregulators, application of 0.50 mg I^?1 brassinosteroid recorded maximum increments in grain yield (14.10%), followed by 10 mg I^?1 kinetin (12.31%) and 1000 mg I^?1 thiourea (9.92%), over control (4.99 t ha^?1). Bioregulators significantly enhanced the uptake of nutrients (N, P, K, S, Zn) over control. NPKSZn treatment also gave the maximum net return (Rs. 51,209 ha^?1). Among the bioregulators, brassinosteroid provided the maximum net return (Rs. 47,292 ha^?1) and benefit:cost (B:C) ratio (3.37) followed by thiourea (Rs. 45,500 ha^?1 and 3.35). Kinetin also provided yield advantage, however, it gave a significantly reduced B:C ratio compared with control.     

Effects of urea nitrogen and residual composted municipal waste and sheep manure on the growth and chemical composition of two triticale genotypes

In 2012, a greenhouse experiment was conducted to investigate the effects of field soil (C0), residual composted municipal waste (CMW), and residual composted sheep manure (SM) on the growth of triticale in pots previously growing oilseed rape in 2011. To each soil group, one of three levels of urea nitrogen (N) fertilizer was added. Results demonstrated that triticale grown in pots previously containing oilseed rape plants containing SM or CMW with 150 kg urea N ha^?1 had the highest N content. Plants grown in SM with 150 kg N ha^?1 had the greatest seed yield, but yield was not significantly different from plants grown in CMW receiving 150 kg N ha^?1. Triticale plants enriched by either SM or CMW had a higher amount of N, copper, zinc, and manganese compared to the field soil control.     

Potassium fertilization and soil diagnostic criteria for forage corn (Zea mays L.) production contributing to lower potassium input in regional fertilizer recommendation

Abstract

Effective soil diagnostic criteria for exchangeable potassium (Ex-K) combined with inorganic potassium (K) application rates were developed to lower K input in forage corn (Zea mays L.) production using experimental fields with different application rates and histories of cattle manure compost. Two corn varieties, ‘Cecilia’ as a low K uptake variety and ‘Yumechikara’ as a high K uptake variety, were selected from among 20 varieties and tested to make diagnostic criteria for K fertilization applicable to varieties with different K uptakes. The K uptakes increased from 96 to 303 kg K ha^?1 for ‘Cecilia’ and from 123 to 411 kg K ha^?1 for ‘Yumechikara’ with increasing Ex-K content on a dry soil basis from 0.11 to 0.92 g kg^?1 with no inorganic K fertilizer application. The K uptake by corn for achieving the target dry matter yield of 18 Mg ha^?1 was estimated to be approximately 200 kg K ha^?1 in common between the two varieties. Yields of both varieties achieved the target yield at an Ex-K content of approximately 0.30 g kg^?1 with no K fertilization, although ‘Yumechikara’ reached the target yield at a lower Ex-K content. At the low Ex-K content of 0.1 g kg^?1, inorganic K fertilizer application at 83 kg K ha^?1 was needed to gain the target yield, and apparent K recovery rate for K fertilizer was calculated to be 70% for both varieties. The K uptakes for gaining the target yield by the K fertilization were lower than that by soil K supply. Based on these results, diagnostic criteria of Ex-K and inorganic K application rates were set up as follows: at an Ex-K content of < 0.15 g kg^?1, inorganic K fertilizer is applied at 83 kg K ha^?1 (100 kg ha^?1 as potassium oxide (K₂O) equivalent); at an Ex-K content of 0.15–0.30 g kg^?1, the application rate is reduced to 33 kg K ha^?1 (40 kg K₂O ha^?1); at an Ex-K content of ≥ 0.30 g kg^?1, inorganic K fertilizer is not applied because of sufficient K in the soil. Additionally, we propose that cattle manure compost be used to supplement soil K fertility.     

Introduction of composted rock phosphate and poultry manure enhances winter wheat phosphorus use efficiency,grain yield and soil quality

This field study evaluates the integrated impact of poultry manure (PM), rock phosphate (RP), composted rock phosphate (CRP) and single super phosphate (SSP) on the growth, yield, and phosphorus use efficiency (PUE) of winter wheat and their effect on postharvest soil characteristics. The seven treatments were as follows: T₁ = control; T₂ = SSP full; T₃ = PM full; T₄ = RP full; T₅ = CRP full; T₆ = 50% SSP + 50% CRP (50:50); T₇ = 50% PM + 50% CRP (50:50) at a recommended P rate of 90 kg ha^?1. The combined treatment with PM + CRP produced the highest straw yield of 3582 kg ha^?1, grain yield of 2226 kg ha^?1, P uptake of 21.3 kg ha^?1, and PUE of 18%. The postharvest soil organic carbon, total nitrogen and soil available phosphorus were sig-nificantly higher in integrated treatments.     

Management practices of macronutrients for potato for smallholder farming system at alluvial soil (Entisols) of India

In the present study, seven fertilizer treatments [T₁, 50% NPK; T₂, 100% NPK (Recommended dose of fertilizer, 200–65.4–124.5 kg N-P-K ha^?1); T₃, 150% NPK; T₄, 100% PK; T₅, 100% NK; T₆, 100% NP and T₇, control (zero NPK)] with four replications were assessed in the new alluvial soil zone (Entisols) of West Bengal, India. The objectives of the study were to generate information on potato productivity, profitability, indigenous nutrient supply and net gain/loss of NPK in post-harvest soil. Plants grown under higher NPK supply resulted in higher tuber yield and there were significant (p ≤ 0.05) reductions in total yield with nutrient omissions. Nutrient?limited yields were 19.78, 2.83 and 1.77 t ha^?1 for N, P and K, considering total tuber yield (28.24 t ha^?1) obtained under 100% NPK as targeted yield. Indigenous nutrient supply of N, P and K were estimated at 24.1, 22.34 and 110.22 kg ha^?1, respectively that indicates higher K?supplying capacity of experimental soil as compared to N and P. Net income (US$1349 ha^?1 year^?1) and B:C ratio (1.91) was highest with 100% NPK, and further addition of NPK (150%) resulted in decrease on net return (US$1193 ha^?1 year^?1) and B:C ratio (1.73).     

Risks of Boron Toxicity in Canola and Lupin by Forms of Boron Application in Acid Sands of South-Western Australia

Boron (B) deficiency frequently occurs on soils that are low in organic carbon (C) (<1.0% organic C), pH (soil pH_Ca <5.0), and clay content (<5% clay). Acid sands with these soil properties are common in south-western Australia (SWA). Moreover, hot calcium chloride (CaCl₂) extractable B levels are commonly marginal in the acid sands of SWA. This study examined the effects of soluble and slow release soil-applied B fertilizer and foliar B sprays on crops most likely to respond to B fertilizer on these soils, canola (oil-seed rape, Brassica napus L.) and lupin (Lupinus angustifolius L.).

At 25 sites over three years, canola was grown with (0.34 kg ha-¹) or without B applied as borax [sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O) 11% B], and this was followed by nine experiments with B rates [0, 0.55, 1.1 kg ha^?1, applied as borax or calcium borate (ulexite, NaCaB₅O₆(OH)₆·5(H₂O), 13% B] and foliar sprays (0.1% solution of solubor, 23% B) in 2000–2001. A further five sites of B rates and sources experiments were carried out with lupin in 2000–2001. Finally, foliar B sprays (5% B w/v as a phenolic complex) at flowering were tested on seven sites in farmers’ canola crops for seed yield increases. No seed yield increases to soil-applied B were found while foliar B application at flowering increased canola seed yield in only one season across seven locations. By contrast, borax fertilizer drilled with the seed at sowing decreased canola seed yield in nine of 34-farm sites, and decreased lupin yield in two of five trials. Toxicity from drilled boron fertilizer decreased yield could be explained by decreases in plant density (by 22–40%) to values lower than required for optimum seed yield. Seedling emergence was decreased by borax applied at sowing but less so by calcium borate. Foliar B spray application never reduced seed yield due to toxicity effects.

Boron fertilizer drilled with the seed increased the B concentration in plant dry matter at early to mid-flowering. Boron application decreased the oil concentration of grain of canola at four sites. The oil yield of canola was significantly decreased at seven sites.

Notwithstanding the marginal B levels on acid sands of the SWA region, care needs to be taken on use of borax fertilizer as toxicity was induced in canola and lupin; with 0.34 to 1 kg B ha^?1(3-10 kg borax ha^?1) at sowing depressing seed yield, mostly by decreasing plant density. Rather than making general recommendation for B fertilizer application based on 0.01M CaCl₂ soil extractable B, soil and plant analysis should be used to diagnose B deficiency and B fertilizer use limited to calcium borate or foliar borax rather than soil-applied borax on low B sands.     

Effect of Cattle Manure and Sulfur on Yield and Oil Composition of Pumpkin (Cucurbita pepo var. Styriaca) Inoculated with Thiobacillus thiooxidans in Calcareous Soil

The effect of cattle manure and sulfur fertilizer on seed yield and oil composition of pumpkin (Cucurbita pepo var. Styriaca) under inoculated with Thiobacillus thiooxidans was investigated in a factorial study based on a randomized complete block design. Experimental factors consisted of cattle manure (M) (M₀: 0, M₁: 10; and M₂: 20 t ha^?1), sulfur (S) (S₀: 0, S₁: 250; and S₂: 500 kg ha^?1) and T. thiooxidans (B): inoculated (B₁) and non-inoculated (B₀). Results demonstrated that the application of T. thiooxidans, cattle manure, and S fertilizer decreased the soil pH. The largest number of seed per fruit (367), highest fruit yield (70.57 t ha^?1), seed iron (Fe) content (16.26 mg 100 g^?1), and seed yield (111 kg ha^?1) was obtained when 20 t ha^?1 manure was applied in combination with 500 kg ha^?1 S inoculated with T. thiooxidans. In this condition, the content of S, Fe, phosphorus (P), and nitrogen (N) in plant shoots was increased by 44.8%, 22.58%, 33.89%, and 10.38%, respectively, compared to the control. Moreover, the highest content of seed protein was observed in 10 t ha^?1 manure and 500 kg ha^?1 S fertilizer inoculated with T. thiooxidans. When 250 kg ha^?1 S fertilizer was applied, 20 t ha^?1 manure decreased seed P content sharply. At the rate of 500 kg ha^?1 S fertilizer, the highest content of seed P was obtained from 20 t ha^?1 manure. Totally, 20 t ha^?1 cattle manure, along with 500 kg ha^?1 S fertilizer as well as T. thiooxidans inoculation, improved oil and seed yield of medicinal pumpkin.     

Boron fertilization improves seed yield and harvest index of Camelina sativa L. by affecting source-sink

The impact of soil (1, 2 kg ha^?1) and foliar (100, 200 mg L^?1) boron (B) with control (no B) was evaluated on phenology and yield formation of Camelina each applied at stem elongation and flowering stages. Foliar (200 mg L^?1) or soil B (2 kg ha^?1) resulted in earlier flowering and maturity, increased fruit bearing branches (19.68%), number of siliqua, seeds per siliqua (4.6%), biological yield (15%), seed yield (24%), harvest index (11.4%) and oil contents (23%) than no B. Increased fruit bearing branches, seed filled siliqua or seed numbers, harvest index and oil quality can be attributed to changes in dry matter accumulated of stem with simultaneous increase in siliqua dry weight with foliar or soil applied B. In crux, foliar (200 mg L^?1) or soil applied (2 kg ha^?1) B seems promising to improve seed and oil yield, harvest index of Camelina sativa under B deficient condition.     

Effects of biochar and poultry manure on soil properties,growth, yield and quality of cocoyam (Xanthosoma sagittifolium Schott) grown in sandy soil

ABSTRACT

Field experiments were conducted during the 2017 and 2018 cropping seasons, to evaluate the effects of biochar (B) and poultry manure (PM) on soil physical and chemical properties, leaf nutrient concentrations, growth, mineral composition and corm and cormel yield of cocoyam. The experiment each year consisted of 4 × 2 factorial combinations of B (0, 10, 20 and 30 t ha^?1) and PM (0 and 7.5 t ha^?1). Results of the study indicated that in both years, the application of B and PM alone, and in combination, improved soil physical and chemical properties, leaf nutrient concentrations, growth, mineral composition and corm and cormel yield of cocoyam. There was a significant interaction effect of B and PM (B x PM) which was adduced to the ability of the B to increase PM-use efficiency and promote better use of the nutrients in the PM. It was found that combination of 30 t ha^?1 B and 7.5 t ha^?1 PM (B₃₀+ PM_7.5) gave the highest corm and cormel yield of cocoyam compared with other treatments. The combination of 30 t ha^?1 B and 7.5 t ha^?1 PM (B₃₀+ PM_7.5) exhibited the highest impact and is therefore recommended for soil sustainability and cocoyam productivity on sandy soil.     

Boron fertilization of Mediterranean aridisols improves lucerne (Medicago sativa L.) yields and quality

Abstract

Lucerne (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires boron (B) addition as the soils are naturally B deficient. Field experiments with four B-application rates (0, 1, 3, and 9 kg ha^?1 B) were conducted in 2005 and 2006 to determine the optimum economic B rate (OEBR), critical soil test and tissue B values for dry matter (DM) production for lucerne grown on B-deficient calcareous aridisols in eastern Turkey. Boron application increased yield at each site in both years of production. The OEBR and critical soil and tissue B content were not impacted by location. Averaged over the two years and three locations, the OEBR was 6.8 kg B ha^?1 with an average DM yield of 12.0 Mg ha^?1. The average soil B content at the OEBR was 0.89 mg kg^?1 while leaf and shoot tissue B content amounted to 51.8 and 35.5 mg kg^?1, respectively. Boron application decreased tissue calcium (Ca), zinc (Zn), and copper (Cu), and increased tissue nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe), and manganese (Mn). Tissue and soil B increased without impacting yield at B levels up to 9 kg ha^?1. We conclude that 7 kg ha^?1 B is sufficient to elevate soil test B levels from 0.11 to 0.89 mg kg^?1 and overcome B deficiency at each of the sites in the study. Similar studies with different soils and initial soil test B levels are needed to conclude if these critical soil and tissue values can be applied across the region.     

Effect of Raw and NH4+-enriched Zeolite on Nitrogen Uptake by Wheat and Nitrogen Leaching in Soils with Different Textures

Leaching of nutrients in soil can change the surface and groundwater quality. The present study aimed at investigating the effects of raw and ammonium (NH₄⁺)-enriched zeolite on nitrogen leaching and wheat yields in sandy loam and clay loam soils. The treatments were one level of nitrogen; Z₀: (100 kg (N) ha^?1) as urea, two levels of raw zeolite; Z₁:(0.5 g kg^?1 + 100 kg ha^?1) and Z_2: (1 g kg^?1 + 100 kg ha^?1), and two levels of NH₄⁺-enriched zeolite; Z₃: (0.5 g kg^?1 + 80 kg ha^?1) and Z₄: (1 g kg^?1 + 60 kg ha^?1). Wheat grains were sown in pots and, after each irrigation event, the leachates were collected and their nitrate (NO₃^?) and NH₄⁺ contents were determined. The grain yield and the total N in plants were measured after four months of wheat growth. The results indicated that the amounts of NH₄⁺ and NO₃^? leached from the sandy loam soil were more than those from the clay loam soil in all irrigation events. The maximum and minimum concentrations of nitrogen in the drainage water for both soils were observed at control and NH₄⁺-zeolite treatments, respectively. Total N in the plants grown in the sandy loam was higher compared to plants grown in clay loam soil. Also, nitrogen uptake by plants in control and NH₄⁺-zeolite was higher than that of raw-zeolite treatments. The decrease in the amount of N leaching in the presence of NH₄⁺-zeolite caused more N availability for plants and increased the efficiency of nitrogen fertilizers and the plants yield.