Crop Nutrient Requirements Research Articles

Estimating Nutrient Uptake Requirements for Potatoes Based on QUEFTS Analysis in China

Excessive or imbalanced fertilization has not only decreased nutrient use efficiency, but also degraded arable land and posed a great threat to the environment. In this study, the datasets were collected from field experiments for the period 1992 to 2017 in the main potato (Solanum tuberosum L.) production regions of China. We used the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model to estimate the soil‐plant balanced N, P, and K requirements for the potato in China. Our results revealed that there were great differences in the potato yield and nutrient uptake. The upper and lower 2.5th percentiles of N, P, and K internal efficiencies (IE, kg tuber per kg nutrient in the total plant) data were used as maximum accumulation (a) and maximum dilution (d) boundary parameters in the QUEFTS model, which were 133 and 463 kg kg–1 for N, 652 and 3030 kg kg–1 for P, and 119 and 790 kg kg–1 for K, respectively. The QUEFTS model predicted plant nutrient uptake of 4.0 kg N, 0.7 kg P, and 3.5 kg K to produce 1 Mg of tuber in the linearly distributed portion, and a corresponding tuber nutrient demand of 2.9 kg N, 0.5 kg P, and 2.3 kg K to produce 1 Mg of tuber. Field validation experiments confirmed that the QUEFTS model could be used to simulate optimum nutrient uptake and provide appropriate parameters in building fertilizer recommendation, which helps improve nutrient use efficiency for potato in China.Core Ideas This is the first report of QUEFTS model on estimating the optimum nutrient requirements for potato crops in China. The datasets used in this study were collected from multi‐year‐site field experiments. Multi‐site field validation experiments in potato‐producing areas confirmed the feasibility of QUEFTS model‐simulated nutrient uptake.

Effect of single and dual bio-inoculants on chemical properties and nutrient availability in soil after harvest of sunflower

Biofertilizers are the alternate sources to meet the nutrient requirement of crops). Biofertilizer like Azotobacter fix atmospheric nitrogen. PSB plays a vital role for making unavailable phosphorus to available phosphorus by mineralization of organic phosphate or by solubilization of inorganic phosphate by production of acids. The nutrient availability after harvest of sunflower noted significantly better in bioinoculant treated plots as compared to uninoculated control and only RDF. Through, liquid inoculants showed better performance but carrier based bioinoculants were also found equally at par with the respective N-fixer and P-solubilizer treatments).

Development and validation of a simulation model for hairy vetch (Vicia villosa Roth) self-regeneration under different crop rotations

Hairy vetch (HV, Vicia villosa Roth) is a winter annual legume cultivated for pasture grazing, in crop rotations with cereal crops under semi-arid conditions. The inclusion of HV increases soil nitrogen, thus contributing to satisfied the nutrient requirements of the successive crops. As a forage crop, HV shows a remarkable capability for natural reseeding. This study aimed to develop and validate a simulation model to evaluate HV self-regeneration capacity considering different HV–winter cereal crop rotation (pasture-crop phase) scenarios. Predicted HV plant density for the evaluated crop sequences matched observed values. HV yield and seed rain were the most important variables affecting seedbank replenishment and self-regeneration capacity. HV monoculture permits successive natural reseeding to reach a basal stand threshold of 30 plants m−2, required for a productive pasture. In a HV-cereal-HV crop rotation, the HV self-regeneration capacity requires a minimum seed yield of 185 and 240 kg ha−1 at the end of the first season under conventional (CT) and no tillage (NT) systems, respectively. Natural seedbank replenishment would not be enough to establish a productive pasture by self-regeneration after two or more successive years of cereals. From a weed management perspective, HV control should not be a considerable problem as a “volunteer plants” if management practices avoid seed production and seedbank replenishment for at least three consecutive years. These outcomes suggest the potential applicability of the proposed modelling approach within management decision support systems.

Biobased Polyurethane, Epoxy Resin, and Polyolefin Wax Composite Coating for Controlled-Release Fertilizer.

Reducing the use of petrochemical products in coated controlled-release fertilizers while regulating the releaserate is a popular research topic in the field of controlled-release fertilizers. In this study, a novel biobased polyurethane (BPU), epoxy resin (ER), and polyolefin wax (PW) composite coating method for the controlled release of urea was successfully established. The method involved: (1) the use of PW as a modified inner coating, which improved fertilizer surface performance and reduced urea surface roughness; (2) the degradable BPU film was synthesized with liquefied starch (LS) as the outer coating material; and (3) epoxy resin is a protective layer, which improved the hydrophobicity of the coated urea for controlled release. The chemical structure, thermostability and microscopic morphology of composite-coated urea (CCU) were examined by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), respectively. A central composite design of response surface methodology was used to examine the effects of different film percentage, PW contents, and BPU/ER ratios on nutrient release behavior. The results showed that PW optimized the fluidity, thermal insulation properties, and microscopic surface of the particles and improved the uniformity of the heating of urea. When the same amount of ER was used, the CCU showed a 3-fold increase in the release period compared to that of the cross-linked interpenetrating coated urea. Polynomial mathematical models were established for CCU preparation and could be an effective tool for manufacturing CCUs with specific nutrient release characteristics that could meet the nutrient requirements of crops in different cropping systems. The new coating method introduced in this study could guide the development of a new generation of biobased controlled-release fertilizers.

ITK adoption pattern of organic farming in Tamil Nadu for the management of shoot and fruit borer, Leucinodesorbonalis Guenee in brinjal crop

Brinjal, Solanum melongena L, is a commercial grown vegetable crop cultivated by the farmers since several years. Farmers relay mainly on pesticides for the management of L. orbonalis, one of the major destructive pest of brinjal. The awareness among the farmers is increasing day by day for organic farming and organic produce, the area under organic farming is in expanding stage in different state in India. The present study was taken to document and to understand the ITK practices of farmers growing organic brinjal in different districts in Tamil Nadu. Majority of the farmers 65.42 per cent who are practicing farmers are medium category land holding of 2 to 10 hectare and 86.70 per cent of farmers interview depend organic agriculture as main source of Income. Use of 14 different soil amendments/ foliar spray to meet out the nutrient requirement of the organic brinjal crop. The cow based ITK product Panchagavya is a major source of nutrient substitute used by 73 percent of the farmers. They use around 14 different ITK concoctions in rotation for the management of L. orbonalis. Most commonly used ITK concoctions were Meenamilam (10 ml /lit),Neem oil (2ml/ lit), Ginger-Garlic extracts (5ml/ lit), Ten leaf extract (16.4%) moor karaisal (100ml/ lit) pungam oil (30ml/lit), tobacco leaf extract (30ml / lit) Agniasthiram (30ml/ lit) and Neemastram (25ml/ lit). A Meenamilam ITK concoctions used by 75 per cent of the farmers across the Tamil Nadu. The present study indicates availability of an array of ITK concoctions used by the organic farmers for the management of L. orbonalis in brinjal. The information generated in the present study will be useful in designing organic IPM module for the pest management in brinjal and organic vegetable cultivation in general.

Microbial Transport as Affected by Residue Cover and Manure Application Rate

Abstract. Manure is applied to cropland areas with varying surface cover to meet single- or multiple-year crop nutrient requirements. The objectives of this field study were to (1) examine microbial transport following land application of manure to sites with and without wheat residue, (2) compare microbial loads following land application to meet the 0, 1, 2, 4, and 8-year P-based requirements for corn, and (3) evaluate the effects of rainfall simulation run on microbial transport. Manure was added and incorporated by disking plots that were 0.75 m wide by 2.0 m long. Three 30 min simulated rainfall events, separated by 24 h intervals, were then applied at an intensity of 70 mm h-1. Plots containing wheat residue had a total coliform load of 12.6 log CFU ha-1, which was significantly greater than the 12.4 log CFU ha-1 measured on the plots without wheat residue. The plots with and without wheat residue had transport rates of and enterococci that were not significantly different. The plots on which manure was added at rates varying from 5.4 to 42.8 Mg ha-1 had counts of total coliforms and enterococci that were not significantly different. Rainfall simulation run did not significantly affect measurements of phages, total coliforms, or enterococci. Transport of selected microbes was found to be significantly affected by residue cover, manure application rate, and rainfall simulation run. Keywords: Bacteria, Cattle manure, E. coli, Feedlots, Land application, Manure management, Manure runoff, Microbial, Microorganisms, Runoff.

Impacts of N‐stabilizers and Biochar on Nitrogen Losses, Nitrogen Phytoavailability, and Cotton Yield in Poultry Litter‐Fertilized Soils

Core Ideas Effect of nitrogen stabilizers were evaluated on nitrogen uptake and yield of cotton in poultry litter fertilized soils. Nitrogen stabilizers effect on nitrogen losses as NH3 and N2O were evaluated from poultry litter fertilized soils. Effect of pine hardwood biochar on nitrogen uptake, yield of cotton, and nitrogen losses were evaluated from poultry litter fertilized soils. Poultry litter (PL) serves as a multi‐nutrient fertilizer. However, compared to inorganic fertilizers, PL requires high rate of application to meet crop nutrient requirements due to relatively low concentration and easy loss of nutrients. A 4‐yr field experiment was conducted with cotton (Gossypium hirsutum L.) to examine the effect of the N‐stabilizers [N‐(n‐butyl) thiophosphoric triamide (NBPT) and dicyandiamide (DCD)], and pine hardwood biochar (PBC) on minimizing N‐losses through NH3 volatilization and N2O emissions, plant nutrient content and agronomic yield in PL applied soils. Application of NBPT to PL was evaluated at 1, 2, and 4 kg ha−1, and NBPT+DCD at 0.22 kg NBPT+2.72 kg DCD and 0.44 kg NBPT+5.44 kg DCD ha−1 with PL only and untreated control treatments. PBC applied to PL was evaluated at 2 and 4 Mg ha−1 along with PBC only at 4 Mg ha−1. The results showed that N‐stabilizers were useful in mitigating PL N‐losses via reducing NH3 volatilization and N2O emissions by up to 12 and 64%, respectively, compared to PL only treatment. N‐stabilizers also improved plant tissue‐N content by up to 5.5% and cotton yields by about 6% over PL treatment. The application of NBPT at 2 kg ha−1 with PL produced higher cotton yield along with lower N losses. For NBPT+DCD, 0.44 kg NBPT+5.44 kg DCD ha−1 with PL performed better than 0.22 kg NBPT+2.72 kg DCD ha−1. PBC was effective in reducing N‐losses through NH3 volatilization and N2O emissions, compared to PL and the untreated control. However, PBC led to reduced N‐availability to plants, as evidenced by lower tissue N‐content and lower cotton yields.

The cost-effectiveness of using latrine dehydrated and pasteurization pellets and struvite: Experimental evidence from South Africa

Faecal sludge and urine can be recycled and processed into usable fertilizer products such as the latrine dehydrated and pasteurization (‘LaDePa’) pellets and struvite, respectively. To quantitatively determine the financial cost effectiveness of using LaDePa and struvite, a study was conducted using experimental data for maize, wheat and sugarcane production in KwaZulu-Natal, South Africa. The costs per hectare of using these potentially new human waste-based fertilizer products to meet crop nutrient requirements for the selected crops and achieve the optimum target yields were determined and compared with the costs per hectare of using recommended commercial fertilizers. The financial feasibility was determined using partial budgets. The results showed that both LaDePa and struvite are financially viable if used in place of the organic fertilizer studied. LaDePa is even more cost effective if it is used as a soil amendment to improve soil physical properties.

Environmental impact of rice production based on nitrogen fertilizer use

While essential to food production, nitrogen (N) fertilizers in agricultural ecosystems are also important sources of environmental pollution nationally and globally. The environmental impact of three N fertilization levels (30, 60, and 90kgha-1) plus a non-N control (0kgha-1) in growing three rice cultivars (cv. Hashemi, cv. Alikazemi, and cv. Khazar) were assessed for 2years in northern Iran, with the methodology of the life cycle assessment (LCA). The impact categories evaluated in this study were global warming, acidification, terrestrial eutrophication, and depletion of fossil, phosphate, and potassium resources. Over cultivars, no use of N fertilizer provided the lowest grain yield (2194kgha-1), whereas the N rates of 60 and 90kgha-1 increased grain yield by 52.9 and 66.9%, respectively. Over N rates, cv. Khazar produced the highest grain yield (3415kgha-1) and cv. Hashemi the lowest (2663kgha-1). On-farm (foreground) emissions were higher than off-farm (background) emissions in most impact categories. The maximum value of environmental index (1.33) was observed for cv. Hashemi with 90kgNha-1, while the minimum value (0.38) was observed for cv. Khazar without N fertilization. Moreover, cv. Khazar showed the lowest resource depletion index (0.44) with 90kgNha-1, whereas cv. Hashemi with no use of N showed the maximum value (0.96). Over cultivars, high N rates imposed drastic impact to the categories acidification and terrestrial eutrophication. However, selection of high-yielding cultivars significantly alleviated the impact to most categories. Fertilization that enables optimal yields, in accordance with the nutrient requirements of crops, ensures the most efficient land use and sustainable rice production.

Impression of Disparate Levels of Poultry Manure and Humic Acid on the Yield and Yield Traits of Maize (Zea Mays L.)

Use of inorganic fertilizers have some problems to farmers in terms of high cost and short residual effect. Since use of organic fertilizers have a long residual effect but the nutrient requirement of crops is not fulfill in one season. So, using of combination of different organic manures can not only improve soil properties but also fulfill the nutrients requirement of crops. Therefore, a study was carried out aiming use of combinations of organic manures to improve maize yield and quality at the Cereal Crops Research Institute (CCRI), Pirsabak District Nowshera, KP, Pakistan during Kharif 2016. Poultry Manure (PM) and Humic Acid (HA) combinations were used as treatments including T1=Control, T2=2.5 tons PM ha-1+5 kg HA ha-1, T3=5 tons PM ha-1+4 kg HA ha-1, T4=7.5 tons PM ha-1+3 kg HA ha-1, T5=10 tons PM ha-1+2 kg HA ha-1 and T6=12.5 tons PM ha-1+1 kg HA ha-1. A basic dose of NPK was applied at the rate of 60:40:30 kg N, P and K ha-1. The results showed that highest days number to tasseling (55) and to silking (56) were recorded when PM and HA were applied at the rate of 12.5 tons PM ha-1+1 kg HA ha-1 as compared with control plots. Highest plant height (185.33 cm), leaf area (411.26 cm2), cob length (17.0 cm), grains number cob-1 (413), grain yield (4783.3 kg ha-1), 1000 grain weight (413 g) and stover yield (13197 kg ha-1) were produced when PM and HA were applied at the rate of 12.5 tons PM ha-1 and 1 kg HA ha-1 as compared with the control plots. It is recommended that use of HA and PM in blending not only improves crop yield but also has a long term residual effect and improve soil properties as well.

Soil Chemical Characterization and Fertility Status in Selected Irrigation Schemes in Unguja and Pemba Isles, Zanzibar

A survey was undertaken to assess the soil chemical properties and fertility status in selected irrigation schemes in Unguja and Pemba Isles in October, 2017 during the short rainy seasons. These schemes include Dobi, Kwalempona, Machigini and Ole in Pemba and Bandamaji, Kibonde Mzungu, Koani, Mchangani and Mtwango in Unguja. Soil sampling was done after the soils were grouped into similar pedons following pedogeomorphic approach whereby fifteen and ten mapping units were delineated in Pemba and Unguja respectively. Using zigzag sampling techniques, nineteen composite samples were collected in quadruplicate at a depth of 0 – 30 cm from the delineated pedogeomorphic units at a radius of 20 m around the soil pits. Soil samples were bulked, thoroughly mixed, sub sampled to obtain a representative sample, packed and sent to NSS laboratory for analysis. The results showed significant difference in fertility status in the selected irrigation schemes. The pH was rated as neutral to strongly acid and or very strongly acid. Of the 25 surveyed mapping units (MUs), 47% were rated as medium acid, 26% as strongly acid, 11% as slightly acid and neutral and 5% as very strongly acid. Per cent OC was high in 21%, medium in 63% and low in 16%. In Machigini irrigation scheme, a third of the MUs was rated as having high % OC compared with the two thirds with medium values. Nitrogen was very low in 89% and low in 11% of the surveyed MUs. Whereas that all the surveyed MUs had N below the threshold value (< 2 g kg-1), 84% had low P and 16% has medium levels of available P. CEC values were rated as medium in 32%, high in 16% and very high in 53% of the MUs surveyed. The C:N ratio suggested that SOM was of poor quality in 89% and moderate in 11% of MUs and all the MUs had C/N ratio outside the suggested range. Nutrient balance shows that Ca/Mg ratio in 58% of the MUs was optimal for most crops and 42% was non-optimal. In conclusion, the soil fertility status and overall information from this study could be used in project irrigation design and fertilizer management studies to establish nutrient and drainage requirements for rice and other crops grown in these areas.

Performance of bell pepper (Capsicum annuumL .) and its economics with different irrigation regimes and nutrient scheduling under protected structure in Island ecosystem

An experiment was conducted to evaluate the effect of irrigation and nutrient scheduling on the yield and economics of bell pepper ( Capsicum annuum L.) under protected structure during 2014 and 2015 at Calicut village, Andaman and Nicobar Islands. Four regimes of irrigation based on IW/CPE ratio (I 1 -0.25; I 2 -0.50; I 3 - 0.75 and I 4 -1.0) and nutrient levels consisted of five different composition of fertilizers to supplement the nutrient requirement of crop was used to find out the best treatment (N 1 -100% recommended dose of NPK (inorganic form); N 2 -50% of inorganic NPK + 50% organic manure; N 3 - 75% of inorganic NPK + 25% organic manure; N 4 -25% of inorganic NPK + 75% organic manure; N 5 -100% organic manure). Combined variance analysis indicated that experimental seasons were not significantly different, but irrigation intervals and nutrient level both significantly influenced the performance and the total capsicum yield. Highest yield was recorded from the combination of irrigationat 0.75 IW/ CPE ratio and nutrient application of 100 per cent recommended dose of NPK (inorganic form) (I 3 N 1 ) treatments at par with the treatment of irrigation at 1.0 IW/CPE ratio and nutrient application of 100 per cent recommended dose of NPK (I 4 N 1 ). However, with the lower irrigation frequency (I 1 ), lower yields were obtained with all nutrient levels. Both I and N significantly influenced the fruit weight, number of fruits per plant branches, quality of fruit and the total yield. The cost benefit ratio of 2.2:1 was recorded in the I 3 N 1 (irrigationat 0.75 IW/CPE ratio and nutrient application of 100% recommended dose of NPK). Therefore, the conclusion, I 3 N 1 treatment is recommended for naturally ventilated polyhouse grown bell pepper in this Island ecosystem in order to attain higher yields with improved quality.

Fertilizer performance of liquid fraction of digestate as synthetic nitrogen substitute in silage maize cultivation for three consecutive years

Following changes over recent years in fertilizer legislative framework throughout Europe, phosphorus (P) is taking over the role of being the limiting factor in fertilizer application rate of animal manure. This results in less placement area for spreading animal manure. As a consequence, more expensive and energy demanding synthetic fertilizers are required to meet crop nutrient requirements despite existing manure surpluses. Anaerobic digestion followed by mechanical separation of raw digestate, results in liquid fraction (LF) of digestate, a product poor in P but rich in nitrogen (N) and potassium (K). A 3-year field experiment was conducted to evaluate the impact of using the LF of digestate as a (partial) substitute for synthetic N fertilizer. Two different fertilization strategies, the LF of digestate in combination with respectively animal manure and digestate, were compared to the conventional fertilization regime of raw animal manure with synthetic fertilizers. Results from the 3-year trial indicate that the LF of digestate may substitute synthetic N fertilizers without crop yield losses. Through fertilizer use efficiency assessment it was observed that under-fertilization of soils with a high P status could reduce P availability and consequently the potential for P leaching. Under conditions of lower K application, more sodium was taken up by the crop. In arid regions, this effect might reduce the potential risk of salt accumulation that is associated with organic fertilizer application. Finally, economic and ecological benefits were found to be higher when LF of digestate was used as a synthetic N substitute. Future perspectives indicate that nutrient variability in bio-based fertilizers will be one of the greatest challenges to address in the future utilization of these products.

Optimizing the phosphorus use in cotton by using CSM-CROPGRO-cotton model for semi-arid climate of Vehari-Punjab, Pakistan.

Crop nutrient management is an essential component of any cropping system. With increasing concerns over environmental protection, improvement in fertilizer use efficiencies has become a prime goal in global agriculture system. Phosphorus (P) is one of the most important nutrients, and strategies are required to optimize its use in important arable crops like cotton (Gossypium hirsutum L.) that has great significance. Sustainable P use in crop production could significantly avoid environmental hazards resulting from over-P fertilization. Crop growth modeling has emerged as an effective tool to assess and predict the optimal nutrient requirements for different crops. In present study, Decision Support System for Agro-technology Transfer (DSSAT) sub-model CSM-CROPGRO-Cotton-P was evaluated to estimate the observed and simulated P use in two cotton cultivars grown at three P application rates under the semi-arid climate of southern Punjab, Pakistan. The results revealed that both the cultivars performed best at medium rate of P application (57kgha-1) in terms of days to anthesis, days to maturity, seed cotton yield, total dry matter production, and harvest index during 2013 and 2014. Cultivar FH-142 performed better than MNH-886 in terms of different yield components. There was a good agreement between observed and simulated days to anthesis (0 to 1day), days to maturity (0 to 2days), seed cotton yield, total dry matter, and harvest index with an error of -4.4 to 15%, 12-7.5%, and 13-9.5% in MNH-886 and for FH-142, 4-16%, 19-11%, and 16-8.3% for growing years 2013 and 2014, respectively. CROPGRO-Cotton-P would be a useful tool to forecast cotton yield under different levels of P in cotton production system of the semi-arid climate of Southern Punjab.

A County-Level Assessment of Manure Nutrient Availability Relative to Crop Nutrient Capacity in Iowa: Spatial and Temporal Trends

Abstract. During the twentieth century, U.S. agriculture strived to achieve increased food production in order to satisfy both local and export demands. In many cases, this led to increased farm sizes and an operational separation of crop and livestock production. The trend of increasing centralization and industrialization of agriculture, specifically animal agriculture, has resulted in the concentration of waste products associated with animal production (manures and wash-down water) over relatively small geographic areas that are spatially segregated from crop production areas. Because the distance that manure can be economically hauled for land application has practical limits, the public is concerned that this spatial separation of crop and animal production areas could lead to over-application of manures near animal feeding facilities, and thus potentially increase the transport of nutrients to ground and surface waters. An aggregated analysis (statewide) of crop and animal production in Iowa suggests that about 30% to 40% of current nitrogen and phosphorus requirements for crop production could be supplied from manures and litters generated from livestock production, while about 50% of potassium requirements could be supplied. However, neither livestock nor crop production in Iowa is uniformly distributed across all counties. This unequal distribution suggests that a more disaggregated analysis of crop nutrient requirements and manure nutrient supply is necessary to estimate the risks of excess nutrient loss to the environment. Thus, we evaluated crop nutrient demand and manure and litter production at the county level to determine if excess manure generation is of concern and to locate areas where additional manures could be used. Results showed that several counties are becoming manure rich, but most locations maintain sufficient capacity to use manure nutrients effectively. Keywords: Crop nutrient capacity, Manure management, Manure production, Nutrient balance, Nutrient management.

Compost de residuos de champiñón como mejorador de suelo y biofertilizante en producción de tomate

Residual mushroom waste has the potential to be composted. Sustainable agriculture considers compost and vermicompost as alternatives to be incorporated into organic vegetable production. The aim of this study was to determine the effect of compost (T2), vermicompost tea (T3), compost extract (T4), and their combination plus the addition of an inorganic element (urea) (T5), against a conventional control (T1), on soil properties and yield parameters of tomato plants grown under shade house conditions. Organic matter, moisture, pH, electrical conductivity (EC), cation exchange capacity (CEC), bulk density, leaf nutrient content during flowering (N, P, K, Ca, Mg, Cu, Fe and Zn), chlorophyll content (SPAD units), fruit number and weight, and yield were the variables assessed during this research. A completely randomized experimental design was used. The organic applications showed significant increases in soil moisture (25.4 % T3), EC (0.38 dS·m-1 T5), and CEC (38.6 meq·100 g-1 T4). Crop nutrient requirements were achieved 102 days after transplanting. The chlorophyll content ranged between 46.9 and 51.4 SPAD units. The cv “Grandella” fruits attained optimal weight (152 to 155 g). The number of fruits and yield did not statistically differ between treatments; therefore, it was concluded that the organic substances by themselves or in combination with inorganic fertilizers were able to produce the same effect on yield, and also improve the physicochemical characteristics of the soil.

Assessment of Soil Chemical Properties and Fertility in Some Traditional Irrigation Schemes of the Babati District, Manyara Region, Tanzania

Aim: To assess the soil chemical properties and fertility status in selected traditional irrigation schemes in Babati District Council in Manyara Region, Tanzania. Place and Duration of Study: The survey was conducted in Mkombozi, Muungano and Endamajek proposed irrigation schemes, Babati District, in Tanzania during the dry season of 2002. Methodology: Soil sampling was done after the soils were grouped into similar soil types following pedogeomorphic approach whereby eleven (11) mapping units were delineated but only ten (10) mapping units were sampled. Using zigzag sampling techniques, thirty (30) disturbed soil samples were collected at depth 0 – 30 cm from the delineated pedogeomorphic units. The soil samples were bulked thoroughly mixed and sub sampled to obtain a representative composite sample and sent for laboratory analysis at the Selian Agricultural Research Institute (SARI), Arusha, Tanzania. Results: The results showed significant difference in the fertility status in the selected sites of each scheme. Based on guidelines of soil nutrient contents established elsewhere, pH of the soils in the study areas were rated as mildly alkaline in 2% in Endamajek and moderately alkaline in 80% in Muungano, 29% in Mkombozi and 73% in Endamajek. The soils were also rated as strongly alkaline in 66% of the area in Mkombozi. Crop production was moderately constrained by sodicity and strongly sodic in 26.6% of the total surveyed area in Endamajek. TN and OM were low, in Muungano; very low or low to medium,; in Mkombozi and low to medium, in Endamajek respectively. Available P was rated as low in 74% and high in 26% of the area in Muungano; high in Mkombozi as well as medium in Endamajek. Of the total surveyed area, 66% in Mkombozi and 26.6% in Endamajek have low CEC. C/N ratio in 46% of the total area surveyed in Muungano was of good quality suggesting ideal conditions for plant growth as compared with Mkombozi and Endamajek. Results also indicated that Ca: Mg ratios to be less than suggested guidelines in 35% of the surveyed areas in Muungano and all the surveyed areas in Endamajek suggesting that plants would probably respond to the addition of Ca or Mg in such areas. Conclusion: The soil fertility status and overall information from this study could be used in fertilizer and sodicity and/or salinity management studies to establish nutrient and drainage requirements for different crops which are grown in these areas.

Utilization of derivatives from nutrient recovery processes as alternatives for fossil-based mineral fertilizers in commercial greenhouse production of Lactuca sativa L.

The production of vegetables relies on the use of mineral fertilizers which are based either on fossil fuel (e.g., nitrogen fertilizers based on Haber–Bosch process) or on fossil ore deposits (phosphate rock). On the other hand, nutrient recovery processes generate various end and side products that can provide a sustainable alternative for fossil-based mineral fertilizers. Their use however, is currently limited by insufficient knowledge about the properties and the impact of these products on soil quality and crop yield. This research was aimed to evaluate the use of the liquid fraction of digestate, effluent from constructed wetlands originating from a manure/digestate treatment facility, air scrubber water and struvite in the cultivation of lettuce (Lactuca sativa L.) compared to their conventional fossil-based counterparts. In accordance with the crop nutrient requirements, different fertilization treatments were set up in which individual products and combinations were tested. At harvest time, assessment of soil physicochemical properties was conducted, along with crop quality control. Nutrient balances were determined and an economic and environmental assessment was evaluated. There were no significant differences in crop yield and soil quality at harvest time between conventional fossil-based mineral fertilizers and selected bio-based mineral alternatives. Nitrogen and potassium use efficiencies were slightly lower in treatments with bio-based fertilizers. Moreover, economic and ecological assessment have shown higher benefits for the farmer when bio-based alternatives were used as a replacement for synthetic fertilizers. Re-use of these products should be stimulated in European legislation.

Control of “Rind Worms” on Squash with Foliar Applied Insecticides, 2013

“Rind worms” is a term used by growers in south Florida to refer to a complex of at least four lepidopteran pests that damage squash and other cucurbit crops. For this trial at the Southwest Florida Research and Education Center in Immokalee, FL, two raised beds 32 inches wide on 6-ft centers and 430 ft long were prepared with fertilizer (1,000 lb/acre of 10-2-10 NPK) incorporated to cover half anticipated crop nutrient requirements. Beds were fumigated with 100 lbs/acre MBC 50/50 on 17 Aug, two drip tapes …

Estimating nutrient requirements for winter oilseed rape based on QUEFTS analysis

SUMMARYEstimating crop nutrient requirements for winter oilseed rape (Brassica napus L.) is a crucial step in optimizing fertilization to enhance seed yield and improve fertilizer use efficiency. In the present paper, a database composed of 1035 on-farm observations collected from 2005 to 2010 across the major winter oilseed rape production regions in China was used to evaluate internal nutrient efficiencies (kg seed per kg nutrient in plant dry matter); then the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model for winter oilseed rape was developed to describe the nutrient uptake-yield relationship of oilseed rape over a wide range of environmental conditions and predict the nutrient requirements for a target yield. After excluding observations with low harvest index values, &lt;0·20, and excluding 0·025 of the highest and lowest internal nutrient efficiencies, the minimum and maximum internal nutrient efficiencies were estimated as 13·1 and 31·6 kg seed/kg nitrogen (N), 68·9 and 200·3 kg seed/kg phosphorus (P) and 8·9 and 31·1 kg seed/kg potassium (K), respectively. On the basis of the data settings, the balanced N, P and K uptake at different yield potential levels was calculated using a linear–parabolic–plateau curve with the QUEFTS model. Crop nutrient requirements increased linearly until the yield reached approximately 0·60–0·70 of the potential yield, and 46·0 kg N, 8·0 kg P and 57·1 kg K were found to be needed to produce 1000 kg of seed. The corresponding internal nutrient efficiencies were 21·8, 125·1 and 17·5 kg seed/kg N, P and K, respectively. However, when the target yields approached the yield potential, a decrease in internal nutrient efficiencies was detected in the model. The predicted nutrient requirement values simulated by the QUEFTS model compared well with observed values across a range of conditions. To conclude, the QUEFTS model was shown to be a practical and robust tool for assessing the crop nutrient requirements of winter oilseed rape.