Application Of Zn Fertilizers Research Articles

Effect of Soil Application of Zinc on Growth, Yield and Zinc Concentration in Rice Varieties

Zinc (Zn) deficiency is widespread nutrient disorder in lowland rice growing areas in Asia, especially in Bangladesh. Intensive cropping with modern varieties causes depletion of inherent nutrient reserves in soils. The application of Zn fertilizers results in higher crop productivity and increases Zn concentration in crops. A field experiment was conducted to evaluate the effect of Zn application on growth, yield, and grain-Zn concentration in eight varieties of rice. The experiment was laid out in a split plot design with a distribution of Zn rates (0 kg ha-1 and 3 kg ha-1 from ZnO) to the main plots and rice varieties (BRRI dhan49, BRRI dhan52, BRRI dhan56, BRRI dhan57, Kalizira, Biroin, Gainja and Khirshapath) to the sub-plots. Zinc application improved effective tillers hill-1, grains panicle-1 and 1000-grain weight which impacted the grain yield of rice. Among the eight rice varieties, a significant increase of grain yield was recorded in BRRI dhan49, BRRI dhan52, BRRI dhan56 and BRRI dhan57 due to application of Zn. Zinc concentration of grain significantly increased in all rice varieties except Biroin. The highest grain-Zn concentration (19.1 mg kg-1) was noted in BRRI dhan57 with 3 kg ha-1 Zn and the lowest value (11.3 mg kg-1) was observed in BRRI dhan52 without Zn application. The highest percent increase of grain Zn concentration over control was obtained in high yielding rice variety BRRI dhan49 and the lowest Zn concentration was found in local rice variety Biroin.

Maize Yield Response to Zinc Fertilization in Farmer’s Field under Rainfed Condition in Hill Region of Assam, Eastern Himalayan Region

Zinc (Zn) is the micronutrient that most commonly limits maize yields but it receives much less attention than other inputs. The present field experiment was conducted to study the effect of Zn fertilizers on growth and yield of maize in farmer’s field under rainfed condition in hill region of Assam, Eastern Himalayan Region for authenticating Zn fertilizer application in increasing the yield of summer maize in actual farmer’s field condition. The experiment was carried out in 6 locations (as replication) of three villages with four treatments which consist of recommended dose of fertilizer (90:40:40 kg NPK kgha-1), recommended dose of fertilizer with ZnSO4 @15 kg ha-1, Farmers’ practice with ZnSO4 @ 15 kg ha-1 and Farmers’ practice (No application of fertilizers) as control. Maize responded positively to Zn fertilization where the yields increased from 4.62 t ha−1 without Zn to 4.91 t ha−1 with Zn under recommended dose of fertilizers. The yield response of maize to application of Zn only recorded 9.15 % increase in yield in case of farmers practice without any fertilizers. Zn application increased maize yield due to increased cob length, cob diameter, kernel numbers and kernel weight in Zn-deficient soils. The increase in grain yield in case of combined use of fertilizer and ZnSO4 (heptahydrate) was mainly due to significantly more number of kernels per cob (392) as well as kernel weight (120.3 g) over application of fertilizers only i.e. 368 and 108.4 g respectively. The result of the present study reveals that, basal soil application of Zn as ZnSO4 @ 15 kg ha-1 in maize crop along with recommended fertilizers is highly recommended for the soils of North Eastern Hill region of India.

Effect of Zinc Application Strategies on Growth and Yield of Soybean in Central India

Fertilization of soybean with zinc (Zn) had received considerable attention in recent years due to world-wide spread of its deficiency in soils and also due to malnutrition in infants and children’s. Soybean is high nutrient exhausting crop but sensitive to zinc (Zn) deficiency in soil. Application of Zn fertilizers could be a viable option to fulfil this deficiency and also to promote yield and growth parameters. This experiment was conducted at Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur during kharif season of 2019 with fourteen treatments of zinc application strategies [(T1) Absolute control, (T2) recommended dose of fertilizer+ No Zn, (T3) RDF + 5.0 kg Zn ha-1, (T4) RDF + spray of 0.5% ZnSO4 at 35 DAS, (T5) RDF + spray of 0.5% ZnSO4 at 35 and 55 DAS, (T6) RDF + 5.0 kg Zn ha-1 + spray of 0.5% ZnSO4 at 35 DAS, (T7) RDF + 5.0 kg Zn ha-1 + spray of 0.5% ZnSO4 at 35 and 55 DAS, (T8) RDF + Zn solubilizer as soil application, (T9) RDF + 5.0 kg Zn ha-1 + Zn solubilizer as soil application, (T10) RDF + Spray of 0.5% ZnSO4 and 150 ppm salicylic acid at 35 DAS, (T11) RDF + spray of 0.5% ZnSO4 and 150 ppm salicylic acid at 35 and 55 DAS, (T12) RDF + 5.0 kg Zn ha-1 + spray of 0.5% ZnSO4 and 150 PPM salicylic acid at 35 DAS, (T13) RDF + 5.0 kg Zn ha-1 + spray of 0.5% ZnSO4 and 150 ppm salicylic acid at 35 and 55 DAS and (T14) No RDF + 5.0 kg Zn ha-1] which were replicated three times in randomized block design(RBD). Results showed that growth parameters, yield attributes and yield of soybean were significantly affected by zinc application strategies. It was found that treatment of RDF + 5.0 kg Zn ha-1 + spray of 0.5% ZnSO4 + 150 ppm salicylic acid at 35 and 55 DAS (T13) had been found best in terms of growth, yield attributes and yield of soybean.

Influence of boron and zinc on yield, nutrient uptake and quality of strawberry

Strawberry (Fragaria X ananassa Duch.) is responsive to boron (B) and zinc (Zn) fertilizer application. Hence, an experiment was conducted in winter season of 2017-18 and 2018-19 to evaluate the effect of boron and zinc application on yield traits, yields, nutrient uptake and quality of strawberry. The experiment was planned with 16 treatment combinations involving four levels each of boron (0, 1, 2 and 3 kg ha−1) and zinc (0, 2, 3 and 4 kg ha−1) following factorial (4 × 4) randomized complete block design with three replications. As per results, application of B 2 kg ha−1 and Zn 3 kg ha−1 produced highest number of fruits (18.5) and most fruit yield (14.1 t ha−1) with higher total soluble solids (7.50°Brix) and vitamin C (72.0 mg/100 g) and greatest B uptake (0.205 kg ha−1) and Zn uptake (0.192 kg ha−1).The interaction effect of boron and zinc was dominant. The result suggests that combined application of B 2 kg ha−1 and Zn 3 kg ha−1 can increase the quantity and quality of strawberry fruit. The present findings may have potential for the area where imbalance uses of boron and zinc fertilizer in strawberry cultivation.

Combined Effects of Soil Amendment and Zinc Fertilizer on Accumulation and Transportation of Cadmium in Soil-Rice System

A field experiment was conducted in moderately and severely Cd contaminated paddy fields in Beishan Town, Changsha City, Hunan Province. This study examined the effects of LS amendment (limestone+sepiolite), in combination with soil application and foliar spraying of Zn fertilizer, on Cd uptake in early and late rice plants. The results showed that: ① the application of LS (2250 kg·hm-2 and 4500 kg·hm-2) significantly increased pH and CEC values in paddy soil during the early and late rice seasons, but the addition of Zn fertilizer (90 kg/hm2) to soil and through foliar spraying (0.2 g·L-1 and 0.4 g·L-1) had no significant effects on the pH or CEC of the soil. ② LS application decreased concentrations of TCLP-Cd and CaCl2-Cd in the soils, by 11.5%-38.8% and 24.0%-81.0%, respectively, while neither of the treatments involving the addition of Zn fertilizer to soil or through foliar spraying had any significant effects on the concentrations of TCLP-Cd and CaCl2-Cd. ③Single treatments involving only LS amendment, Zn fertilizer in soil, or foliar spraying of Zn fertilizer also reduced Cd concentrations in brown rice, but to a lesser degree than the combined treatments. The combined treatments (L1Z1F1, L1Z1F2, L2Z1F1, and L2Z1F2) reduced Cd concentrations in brown rice by 64.9%-67.5% and 56.1%-80.6%, for early and late rice, respectively, while L2Z1F1 (4500 kg·hm-2 LS+90 kg·hm-2 Zn fertilizer+foliar spraying 0.2 g·L-1 Zn fertilizer) resulted in the largest reduction in Cd concentration in brown rice. ④ The Cd/Zn ratio in brown rice was significantly positively correlated with Cd concentrations, indicating that increased Zn concentration in different rice tissues was one of the key reasons for decreased Cd concentration in brown rice. Clearly, as a remediation technology, combining LS amendments with zinc fertilizer is an effective method for achieving the safe utilization of moderately and severely Cd contaminated paddy fields, by effectively inhibiting the uptake, accumulation, and transportation of Cd in rice plants and decreasing Cd concentrations in brown rice.

Response of Rice (Oryza sativa L.) to Soil and Foliar Application of Nano-ZnO and Bulk Zn-fertilizer in Red Acidic Soil of West Bengal, India

In cereal crops Zinc (Zn) deficiency has become a major problem which causes reduction in yield and nutritional quality of the cereal grain, thus affecting human health. Being an essential micronutrient for the production of rice crop, Zn deficiency appears to be an acute problem for the human population whose staple food is rice. Small increase in the nutritive value of rice can thus contribute to the human nutrition. Thus, increasing the micronutrient content of a food crop with the help of enriched fertilizers appears to be an effective way. During two successive growing seasons (wet season, 2017 and dry season, 2018) at the experimental farm of Palli Siksha Bhavana, Visva-Bharati, West Bengal, India, field experiments were carried out to assess the potential of Zn fertilizer on plant height, grain quality, leaf chlorophyll and leaf Zn content of rice plant (Oryza sativa L.) variety MTU-1010 by application of foliar Nano-ZnO (Zinc oxide) and soil ZnSO4.7H2O (Zinc Sulphate Hepta Hydrate). In both seasons, each experiment was conducted in a randomized block design (RBD) with three replicates. Soil Zn as ZnSO4.H2O applications were assigned in the plots at the rate of 5 kg/ha and 0.30% nano-ZnO were assigned as foliar Zn spray along with the basal doses of 80 kg nitrogen (N), 40 kg phosphorus (P2O5) and 40 kg potassium (K2O)/ha as per the treatment details. After 15 days, 30 days, 45 days from transplanting and at the time of flowering as well as post-flowering chlorophyll (a, b, a+b) and Zn in rice plant leaves were determined. Plant heights were recorded after 30 days, 60 days and 90 days from transplanting and at the time of harvest. Quality parameters such as amylose, starch and crude protein content of the grain samples were determined at harvest stage. The results obtained from present assessment showed that, application of soil as well as foliar Zn resulted in significant increase in leaf Zn content, chlorophyll content, grain crude protein and plant height compared to the control. No significant effect on starch and amylose was recorded with Zn fertilization. Foliar spraying with 0.30% nano-ZnO at the time of flowering and post flowering showed a significant augmentation in leaf Zn concentration, chlorophyll content, plant height and quality of rice grain compared to the treatments receiving soil Zn application. Therefore it is considered as a more beneficial treatment in the cultivation of rice plants to promote plant growth and quality.

The reduction of physiological disorder of pomegranate white arils by foliar application of Fe and Zn fertilizer

The reduction of physiological disorder of pomegranate white arils by foliar application of Fe and Zn fertilizer

Performance and quality attributes of okra (Abelmoschus esculentus (L.) Moench) fruits grown under soil applied Zn-fertilizer, green biomass and poultry manure

Field experiments were carried out in 2018 and 2019 cropping seasons at Landmark University Teaching and Research farm, Omu-Aran Kwara state, Nigeria, to determine the effect of soil applied Zn-fertilizer, Tithonia diversifolia (Ti), Chromolaena odorata (Ch) and poultry manure (PM) on the performance, yield, minerals and vitamins composition of okra fruits. Treatments were combined and tested as follows:—Control (T1), Control + 10 kg ha−1 Zn (T2), 5 t ha−1 Ti + 5 t ha−1 PM (T3), 5 t ha−1 Ch + 5 t ha−1 PM (T4), 5 t ha−1 Ch + 5 t ha−1 Ti (T5), 10 t ha−1 Ti + 0 kg ha−1 Zn (T6), 10 t ha−1 Ti + 10 kg ha−1 Zn (T7), 10 t ha−1 Ch + 0 kg ha−1 Zn (T8), 10 t ha−1 Ch + 10 kg ha−1 Zn (T9), 10 t ha−1 PM + 0 kg ha−1 Zn (T10), and 10 t ha−1 PM + 10 kg ha−1 Zn (T11). The experiment was laid out in a randomized complete block design with four repetitions. Vegetative, yield and quality parameters of okra were taken. Data were subjected to analysis of variance and means were compared using Duncan Multiple Range Test (DMRT) at p ≤ 0.05. Variations were observed on the vegetative parameters, yield, minerals and vitamin composition of okra among the applied amendments. The combined application of green biomass, poultry manure, and Zn-fertilizer improved all the variables tested as compared to when they were applied singly. Application of Zn-fertilizer to some selected plots significantly increased yield, Zn, Mg and vitamins concentration of okra. Application of 5 t ha−1 Ti + 5 t ha−1 PM + 10 kg ha−1 Zn (T3) and 5 t ha−1 Ch + 5 t ha−1 PM + 10 kg ha−1 Zn (T4) significantly improved all the parameters tested but the use of 5 t ha−1 Ti + 5 t ha−1 PM + 10 kg ha−1 Zn (T3) resulted in optimum yield and at the same time increase minerals and vitamin concentration of okra. The results of this study therefore showed that Tithonia diversifolia (Ti) as green biomass contained and released more and quality nutrients than Chromolaena odorata (Ch) when combined with equal rate of Zn fertilizer and poultry manure.

Improving Grain Zinc Concentration in Wetland and Upland Rice Varieties Grown under Waterlogged and Well-Drained Soils by Applying Zinc Fertilizer

The objective of this study was to evaluate the responses in grain yield and zinc concentration of wetland and upland rice varieties to Zn fertilizer application and different growing conditions. The wetland (Chainat 1; CNT1) and upland (Kum Hom CMU; KH CMU) rice varieties were grown under waterlogged and well-drained soil conditions with or without Zn fertilizer application. Zinc fertilizer (ZnSO4) was applied at 0 and 60 kg ha−1 in three stages at tillering, booting, and flowering. In the wetland variety, CNT1, grain yield decreased by 18.0% in the well-drained soil compared to the waterlogged conditions, but there was an 8.9% decrease in grain yield in the waterlogged soil compared to the well-drained soil in the upland variety, KH CMU. Applying Zn fertilizer affected yields differently between the varieties, decreasing grain yield by 11.9% in CNT1 while having no effect in KH CMU. For grain Zn concentrations in brown rice, applying Zn fertilizer increased Zn concentration by 16.5–23.1% in CNT1 and KH CMU under both growing conditions. In the well-drained soil, applying Zn fertilizer increased straw Zn concentration by 51.6% in CNT1 and by 43.4% in KH CMU compared with the waterlogged conditions. These results indicated that the wetland and upland rice varieties responded differently to Zn fertilizer application when grown in different conditions. Applying Zn fertilizer in the appropriate rice variety and growing conditions would help farmers to improve both the desirable grain yield and Zn concentration in rice.

Interaction of Genetic and Zn Fertilizer Application on Rice Yield and Grain Zinc Content

The prevalence of Zn deficiency in Indonesia is considerably high. Development of variety having high nutrient or called as biofortification supposed to be effective and efficient to combat malnutrition such as Zn deficiency. Zn fertilizer application was reported to be effective to increase rice Zn content. ICRR in collaboration with IRRI and Harvest Plus had initiated testing rice genotypes having high Zn content. The aim of this research was to initially study of Zn fertilizer, especially ZnSO4, effect to Zn content in the rice grains and to select genotypes having high the Zn content. The trial was conducted during Wet Season 2016 in Subang, West Java following split plot design of three replications with main plot of two level ZnSO4 fertilizer applications and sub plot of 24 rice genotypes. Transplanting was conducted at 21 days after sowing into 2 m x 3 m plot with planting space of 20 cm x 20 cm. The results showed that there is interaction between genotype and Zn fertilizer on yield but not on Zn content in rice grains. Zn fertilization tends to increase grain Zn content and yield. IR97477-115-1-CRB-0-SKI-1-SKI- 0-2 (5.45 t/ha, 33.65 ppm), IR97477-81-2-CRB-0-SKI-0-SKI-0-2 (5.30 t/ha, 33.40 ppm), and IR97477-115-1-CRB-0-SKI-3-SKI-0-2 (5.56 t/ha, 32.48 ppm) has either high yield or Zn content and prospective for further testing. Correlation analysis showed that Zn is strongly correlated with Fe content. Yield is positively correlated with tiller number and Fe content and negatively correlated with heading date, maturity, plant height, and number of unfilled grain/panicle.

Foliar application of glycinebetaine and Zn fertilizer improves both the apparent and functional qualities of albino tea [Camellia sinensis (L.) O. Kuntze

With Zn deficiency increasing in the global population, functional plant food (including tea) can help to fill the nutrition gap that the main crops cannot meet. Glycinebetaine (GB), an important bioactive substance with a wide range of natural sources, has received limited attention towards its effects on Zn biofortification and the quality of tea. The Zn enrichment and metabolite responses of albino tea [cv. White leaf No. 1 (WL-1)] to the foliar application of GB, Zn, and their combination (Zn + GB) were investigated in a field experiment. The result indicated that the 100-buds weight, total N, Zn, Thea, and total amino acid content in the young leaves of WL-1 with Zn2 + GB2 treatment were significantly increased, whereas the Chla contents were decreased (p < 0.05). The total catechins and CAF contents of Zn2 + GB2 treatment were lower than those of other treatments, with significance (p < 0.05). Multivariate analysis and general quantitative analysis returned complementary results, revealing that Zn2 + GB2 treatment was better for the apparent and functional quality of WL-1. The more theanine and Zn, limited chlorophyll, catechin, and caffeine contributed to the quality improvement, as well as to maintaining the leaf albinistic characteristics, inhibiting astringency and bitterness, exerting flavor and umami, and improving the ultimate beneficial functions. The combined application of Zn and GB is a promising practice for Zn biofortification and for the quality improvement of tea, with spraying 750 L ha-1 of 2.0 g L-1 Zn fertilizer and 3.2 g L-1 GB mixture recommended.

Quantifying spatial variability of available zinc in alluvial soils of Brahmaputra plains, India

Occurrence of zinc (Zn) deficiency in soils and plants has been accounted for worldwide including northeastern India. The present study was conducted to determine the spatial distribution and degree of risk of Zn deficiency in Brahmaputra plains of northeastern India using statistics and geostatistics. With the help of handheld global positioning system (GPS), 5494 soil samples were collected using 1 km x 1 km grid at 0–25 cm depth from three districts of Assam state of India namely, Tinsukia, Morigaon and Nalbari representing upper Brahmaputra valley zone (UBVZ), central Brahmaputra valley zone (CBVZ) and lower Brahmaputra valley zone (LBVZ) covering 6249 km2 area and analyzed for pH, organic carbon (OC) and Zn. Dataset was normally distributed. Geo statistical analyses were carried out, including experimental variogram and model fitting. Analysis of the isotropic variograms indicates that the range values of 3900, 4400 and 5800 m for UBVZ, CBVZ and LBVZ, respectively. It implies that the length of the spatial autocorrelation was much longer than the sampling interval of 1 km. The nugget/sill ratio was 0.506, 0.859 and 0.589 for UBVZ, CBVZ and LBVZ, respectively and it indicates moderate spatial dependence. Further, with the ordinary kriging, spatial distribution map showed that the Zn is deficient for plants in the all the three zones of Brahmaputra plains. The probability map produced based on indicator kriging showed that Zn deficiency was noticed in 34% of crops grown area of the Tinsukia, 70% crops grown area in Morigaon and 85% of crops grown area in Nalbari districts. The correlation analysis showed that Zn was significantly and positively correlated with OC and significantly and negatively with pH in Brahmaputra plains. Thus, the present study is of immense help to minimize both yield loss and environmental threats of Zn toxicity due to under or overdose of Zn fertilizer application in Brahmaputra plains of northeastern India.

Nutraceutical Properties of Pecan Kernels Are Affected by Soil Zinc Fertilizer Application

Pecan (Carya illinoinensis) has high kernel antioxidant activity and unsaturated fatty acid content, which contribute to its nutraceutical properties. In the western United States, where soils are typically alkaline, pecan trees require frequent zinc (Zn) fertilizer applications to maintain normal canopy growth and nut production. Our objective was to investigate the effects of tree Zn fertilization on nutraceutical properties of ‘Wichita’ and ‘Western’ pecan kernels. Trees were fertilized with ethylenediaminetetraacetic acid (EDTA) chelated Zn, which was applied to the soil at one of three seasonal rates for a total of three treatments: 0 (control), 2.2, or 4.4 kg·ha−1 Zn. Nut samples were collected and homogenized for analyses of kernel oil yield, hydrophilic antioxidant capacity, fatty acid profile, and γ-tocopherol content. Although soil Zn treatments did not significantly affect antioxidant capacity of defatted pecan kernels, Zn application had significant positive effects on both total kernel oil yield and γ-tocopherol content compared with the control. In conclusion, soil application of Zn fertilizer may increase the human health-promoting aspects of pecan kernels, a valuable attribute among health-conscious consumers.

The effectiveness of foliar applications of different zinc source and urea to increase grain zinc of wheat grown under reduced soil nitrogen supply

Nitrogen is important for the enrichment of grain Zn when Zn is foliarly applied. However, decreasing soil N input has become a major issue for environmental protection. A 2-yr field experiment was conducted to evaluate the effectiveness of spraying different Zn sources [ZnSO4 or Zn(Gly)2] combined with or without urea on grain Zn concentration and bioavailability under reduced soil N rates, both in single wheat plantation and winter wheat-summer maize rotation. Results showed that foliar application of Zn(Gly)2 significantly increased grain Zn concentration by 88% under wheat-summer maize rotation and 150% under single wheat plantation. The effectiveness of foliar ZnSO4 application in increasing grain Zn was similar with that of Zn(Gly)2. Adding urea to foliar ZnSO4 or Zn(Gly)2 further increased grain Zn concentration under reduced soil N rates. Grain Zn biavailability increased with the reduction of soil N rates, but decreased after application of foliar Zn fertilizers. Foliar fertilization significantly increased protein, Fe, and Mn concentrations in grain, and the magnitudes of these increases were greater when Zn(Gly) 2 alone or ZnSO 4 plus urea were applied. Simultaneous foliar application of ZnSO4 and urea slightly increased farmer’s net income. These results suggest that foliar application of ZnSO 4 plus urea can be used as efficient and economical fertilization strategies to increase Zn concentration and bioavailability in wheat grain under reduced soil N supply, and consequently minimize Zn deficiency in humans.

Impact of Coating of Urea with Bacillus-Augmented Zinc Oxide on Wheat Grown under Salinity Stress.

Zinc (Zn) availability is limited in salt-affected soils due to high soil pH and calcium concentrations causing Zn fixation. The application of synthetic Zn fertilizer is usually discouraged due to the high cost and low Zn use efficiency. However, salt-tolerant Zn-solubilizing bacteria (ZSB) are capable of solubilizing fixed fractions of Zn and improving fertilizer use efficiency. In the current study, a product was formulated by coating urea with bioaugmented zinc oxide (ZnO) to improve wheat productivity under a saline environment. The promising ZSB strain Bacillus sp. AZ6 was used for bioaugmentation on ZnO powder and termed as Bacillus sp. AZ6-augmented ZnO (BAZ). The experiment was conducted in pots by applying urea granules after coating with BAZ, to evaluate its effects on wheat physiology, antioxidant activity, and productivity under saline (100 mM NaCl) and non-saline (0 mM NaCl) conditions. The results revealed that the application of BAZ-coated urea alleviated salt stress through improving the seed germination, plant height, root length, photosynthetic rate, transpiration rate, stomatal conductance, soil plant analysis development (SPAD) value, number of tillers and grains, spike length, spike weight, 1000-grain weight, antioxidant activity (APX, GPX, GST, GR, CAT, and SOD), and NPK contents in the straw and grains of the wheat plants. Moreover, it also enhanced the Zn contents in the shoots and grains of wheat by up to 29.1 and 16.5%, respectively, over absolute control, under saline conditions. The relationships and variation among all the studied morpho-physio and biochemical attributes of wheat were also studied by principal component (PC) and correlation analysis. Hence, the application of such potential products may enhance nutrient availability and Zn uptake in wheat under salt stress. Therefore, the current study suggests the application of BAZ-coated urea for enhancing wheat’s physiology, antioxidant system, nutrient efficiency, and productivity effectively and economically.

Determining Mehlich‐3 and DTPA extractable soil zinc optimum economic threshold for maize

AbstractMaize (Zea mays L.) is one of the most susceptible crops to zinc (Zn) deficiency. However, in much of the world, soil Zn tests are poorly calibrated, and thus determining a critical soil test, level for Zn is challenging. The objectives of this study were to: (i) produce a field calibration of the Zn Mehlich‐3 (M3‐Zn) method for predicting maize grain yield response to Zn fertilizer application, (ii) compare the capacity of DTPA extractable Zn (DTPA‐Zn) with M3‐Zn for predicting the response of maize yield to Zn fertilizer, (iii) determine whether inclusion of soil pH, organic matter (SOM) and extractable phosphorus in a M3‐Zn model improves its predictive capacity and (iv) evaluate an economic approach for determining soil Zn thresholds. We conducted 55 field experiments covering a wide range of edaphic and climatic conditions. Maize responded to Zn fertilizer in 29% of the trials. The capacity of M3‐Zn and DTPA‐Zn to predict relative yield of maize was similar. Inclusion of other soil variables (pH, extractable phosphorus and SOM) did not or only slightly improve the prediction of M3‐Zn. Based on the relationship between M3‐Zn and DTPA‐Zn (R2 = 0.89), one test can be predicted from the other without affecting the calibration. The M3‐Zn 'economic threshold' ranged from 0.98 to 2.79 mg kg−1, while for DTPA‐Zn it varied from 0.41 to 1.61 mg kg−1. The broad range of economic thresholds shows that differences in maize productivity and grain price between regions and seasons make establishing a single Zn threshold for all economic‐productive situations inappropriate.

The Development of a Model for Recommending the Application of Zinc Fertilizer in the Mediterranean Region of Central Chile

The main aim of this study is to develop a mechanistic model of fertilization for recommending the application of zinc (Zn) fertiliser for maize based on the mass balance of Zn. The model would consider the critical Zn level for maize (ZnCL), Zn availability in the soil (ZnA) and Zn buffering capacity (Znb). Soil samples were collected from 78 maize fields for chemical and physical characterization including measuring ZnA and Znb. Additionally, a crop management survey was carried out in each field. The classification and regression trees method (CART) was used and relationships between Znb and some soil properties were established, clay content being the most relevant to the model, besides soil reaction (pH) and silt content. The application of Zn fertilizer can be adequately calculated by a mechanistic model that considers ZnA, Znb and ZnCL above that which maize crop yields do not increase. This work highlights the importance of Znb evaluation by the incubation procedure and the extraction of available Zn by DTPA solution. As hypothesised and then demonstrated in this work, Znb is closely related to soil pH and texture (clay and silt). Our results suggest that, in between 51 and 97% of fields examined, it would be necessary to apply Zn fertilisers to produce the maximum maize yield.

Classification of Pigeonpea (Cajanus cajan (L.) Millsp.) Genotypes for Zinc Efficiency.

Pigeonpea (Cajanus cajan (L.) Millsp.) is grown globally for its protein-rich seed. However, low availability of soil zinc (Zn) adversely affects the seed yield of pigeonpea. The present study was therefore conducted to assess the Zn efficiency of pigeonpea genotypes based on seed yield and seed Zn uptake efficiency. Field experiments were conducted at the Indian Council of Agricultural Research–Indian Institute of Soil Science, Bhopal, India with twenty different pigeonpea genotypes and two levels of Zn application under a split-plot design. The two levels of Zn were low (without application of Zn fertilizer) and high (with application of 20 kg Zn ha−1 (as ZnSO4∙7H2O) as basal soil application, in conjunction with three foliar sprays of 0.50% (w/v) ZnSO4∙7H2O aqueous solution) (with 0.25% lime as neutralizing agent) at flowering, pod formation, and pod filling stages). Application of Zn improved plant height, branches plant−1, pods plant−1, seeds pod−1, and 100 seed weight of pigeonpea genotypes differently. The mean seed yield, seed Zn concentration, and seed Zn uptake of the genotypes increased from 1.71 to 2.12 t ha−1, 32.4 to 43.0 mg kg−1, and 54.9 to 90.6 g ha−1, respectively, with application of Zn. The seed yield efficiency index (SYEI) and Zn uptake efficiency index (ZUEI) of pigeonpea genotypes varied from 67.0 to 92.5 and from 47.0 to 69.9, respectively. Based on SYEI and ZUEI, the genotypes were classified as efficient and responsive (Virsa Arhar-1, GT-1, GT-101, SKNP 05-05, BDN-2, AAUT 2007-04, BSMR 853, T 15-15, DT 23, Pusa 9), efficient and non-responsive (ICPL 87119, PKV Trombay), inefficient and responsive (AKT 8811, Hisar Paras), and inefficient and non-responsive (AAUT 2007-10, JKM 7, Hisar Manak, C 11, Hisar HO2-60, GAUT 93-17). The efficient and responsive genotypes are the most useful as they yield well under low soil Zn conditions and also respond to Zn fertilizer application. The inefficient and responsive genotypes could be utilized for plant breeding programs by plant breeders for identification and utilization of responsive traits.

Implication of Zn fertilizer application on Zn biofortification in bajra (Pennisetum glaucum L.) and its interaction with other micro-nutrients

A field experiment was carried out at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad during kharif 2017 to survey the impact of Zn fertilizer application on the biofortification of bajra variety ICMV-221 and the interaction of Zn with other micronutrients in plant and soil. The experiment was laid out in a randomized block design with three replications. ZnSO4. 7H2O and Zn EDTA was applied @ 0, 5, 10, 15 and 20 kg ha-1 before sowing. The result revealed that Zn content in all plant parts of bajra increased significantly with increase in the Zn fertilizer dose recording maximum at 20 kg ha-1 Zn EDTA application which was a 37% increase in the grain Zn content over control and highest grain yield of 4153 kg ha-1 was observed. As observed from plant and soil nutrient status, Zn showed antagonistic effect on Fe, Cu and Mn at higher doses.

Boron and zinc fertilizer applications are essential in emerging vegetable‐based crop rotations in Nepal

AbstractBackground: Since recently, the traditional rice–wheat rotation systems in Nepal are subject to drastic changes. Progressing urbanisation and shifting consumer preferences drive a replacement of wheat by high‐value vegetables during the cold dry season, particularly in the peri‐urban fringes, while emerging water shortages prevent permanent soil flooding during the monsoon season, leading to partial substitution of lowland rice by less water‐consuming upland crops. Associated changes in soil aeration status affect soil nutrient availability while particularly vegetables enhance the demand for the critically limiting micronutrients boron (B) and zinc (Zn).Aim: In both rice‐ (anaerobic) and maize‐based (aerobic) systems we assessed the differential response of traditional winter wheat in comparison to cauliflower and tomato to applied B and Zn fertilizers.Methods: Experiments were conducted (1) in a pot trial with two contrasting soil types (Acrisol vs. Fluvisol) and (2) in field validation trials at two contrasting sites (representing lowland vs. mid‐hills) in Nepal.Results: The on‐going shift from flooded rice to aerobic maize during the wet season negatively affected dry matter accumulation and grain yield of the dry season wheat, but not of cauliflower and tomato. While Zn application tended to increase wheat yields under field conditions, B application induced no significant effect, irrespective of the soil or production site. However, low to moderate applications of B (2.0–4.4 kg ha−1) and Zn (3.3–4.4 kg ha−1) nearly doubled biomass accumulation and nutrient uptake of vegetables and increased the economic yields of cauliflower and tomato between 8 and &gt; 100%. These responses were generally more pronounced in the Fluvisol than the Acrisol. While overall yields of wheat and temperate vegetables were higher in the cool mid‐hills the relative yield responses to applied B were more pronounced in the lowland than the mid‐hill sites. On average, the partial factor productivities of applied fertilizer were low to moderate in wheat, with 1 and 8 € increase in net revenue per € of investment in B and Zn, respectively. In the vegetables, this partial factor productivity increased to about 4 € €−1 investment with Zn, and reached about 43 € €−1 investment in B, irrespective of the production site.Conclusions: While the application of Zn fertilizers can moderately improve the performance of traditional rice–wheat rotations, B and to a lesser extent Zn application become essential and highly profitable when shifting towards vegetable cropping. The demand for B and Zn fertilizers is foreseen to dramatically increase with progressing urbanisation and the associated shifts in production systems of Nepal.