Soil Chemical Analysis

Nature And Properties Of Soils

Wheat is currently the most important crop in the world in terms of yield, area under cultivation and geographical distribution (all continents and climatic zones except polar regions). It has achieved immense cultural and religious significance and, as pointed out by the authors of this volume, its price and availability have influenced the rise and fall of governments. The present volume should, therefore, be of wide interest as it provides a concise but comprehensive and well balanced account of the production and utilization of wheat, from sowing of the seed to processing of the harvested grain. The contents are divided into 10 chapters which fall into four neat sections. The first chapter introduces wheat as a crop, discussing its origin and outlining the different types and their end use characteristics. It then describes the morphology and development of the crop and introduces the wide range of production systems that are used. These range from intensive systems which are most widely used in Western Europe to reduced input systems which have been introduced over the past decade, driven largely by environmental and consumer concerns. This detailed introduction is followed by three chapters focusing on the characters that determine grain utilization and quality and how they are in turn influenced by the genotype and the environment (climate and nutrition). These lead logically into three chapters dealing with aspects of agronomy including sowing and crop establishment, nutrition and fertilizer use and management of pests and diseases. The latter includes detailed discussions of major fungal pathogens (e.g. mildews, rusts, Septoria, eyespot, take-all) and insect pests (aphids, flies, beetles) and of the control of broad leaved and grass weeds, but also covers viral and bacterial diseases, nematodes, molluscs and plant growth regulators used to control height (chlormequat and ethephon). Finally, three separate chapters consider the post harvest management of the grain including drying and pest control, the utilization of the vegetative parts of the crop as forage and the utilization of the grain for the distillation of alcohol and for fractionation into starch and gluten. Throughout the volume there is a major emphasis on optimising end use quality, reflecting the current competitive climate for growers and grain exporters. The level of coverage is designed to be suitable for undergraduate and postgraduate students in agronomy and I have little doubt that it will become a standard text for many courses. However, it is extensively referenced and will almost certainly be used more widely by lecturers and active research scientists. The authors are to be congratulated in producing an exceptionally attractive and readable volume which integrates a range of science from genetics through agronomy to food science.

Wheat Production and Utilization: Systems, Quality and the Environment.

In the last five decades, nutrient applications to farmlands have significantly improved crop yield and public awareness about nutrient use efficiency (NUE). The crop production system is n...

Nutrient use efficiency (NUE) for sustainable wheat production: a review

The increasing interest in the production of bread wheat (Triticum aestivum L.) with specific quality traits requires a shift from the current breeding goal, being yield, to improved compositional and, consequently, functional traits. Since wheat is a key food crop, this must be attained while maintaining or even further increasing yield. Furthermore, as compositional requirements for specific applications are not well-defined, both protein and gluten content as well as the enzymatic activity remain most important. Given that these traits are majorly impacted by both genotype and environment, it is very complex to predict and ultimately control them. Different strategies, such as applying optimized agronomic practices, can temper these uncontrollable determinants which are equally important to steer wheat quality. As current research on their contribution to specific traits is highly fragmented, this report provides a comprehensive review of the influence of crop husbandry and environmental conditions on ...

Impact of Crop Husbandry Practices and Environmental Conditions on Wheat Composition and Quality: A Review

On-farm field experiments were conducted to assess the effects of nitrogen (N) and phosphorus (P) on yield, yield components, nutrients uptake and use efficiencies, protein content of bread wheat, residual soil nitrogen and phosphorus availability and economic return of fertilizer application. The locations of the experiments were in two nearby farmers' field at Hawzen district, Northern Ethiopia. Factorial combinations of five N levels (0, 46, 69, 92 and 138 kg N/ha) and four levels of P (0, 46, 69 and 92 kg P2O5/ha) were laid out in a randomized complete block design with three replications. Experimental Field 1 was relatively better in its soil fertility than experimental Field 2 especially in its phosphorus availability and cation exchange capacity (CEC). However, both fields were low in their total soil nitrogen content. Grain yield of wheat significantly increased by 46% and 15% in Field 1 and Field 2, respectively at nitrogen application rate of 46 kg N/ha than the control. Nitrogen fertilization increased straw yield significantly only in experimental Field 1. Phosphorus application at a rate of 46 kg P2O5/ha increased significantly grain and straw yields by 38 % and 46 %, respectively in Field 2 than control. It is also economical to apply phosphorus at this rate for such farmers’ field because the grain yield marginal rate of return was 179 %. Consistent results were observed on wheat nutrient uptakes and nutrient use efficiencies. Grain and straw yields of wheat were not significantly affected by the main effect of phosphorus application in Field 1. These results are consistent with the soil analysis result before planting where the soil phosphorus was found to be low in Field 1 and very low in Field 2. Previous management by the farmers may have influenced the soil fertility status. There were no interaction effects of nitrogen and phosphorus to affect wheat productivity and nutrient utilization in both fields. Future approach to soil fertility management should consider the past management history and should also be site specific based on soil fertility assessment. As a result, a combined application of 46 kg N/ha and 46 kg P2O5/ha are recommended to achieve sustainable bread wheat production on the sandy soils of Hawzen district. But in fields with higher initial soil phosphorus level, there is no need of applying phosphate fertilizer.

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Effects of Mineral Nitrogen and Phosphorus Fertilizers on Yield and Nutrient Utilization of Bread Wheat (Tritcum aestivum) on the Sandy Soils of Hawzen District, Northern Ethiopia

Crop rotation is a common practice in the study area, but there is no enough information on the specific rate of nitrogen to be applied after legumes for wheat production. Hence, on farm field experiments were conducted to determine the amount of nitrogen fertilizer rates needed for bread wheat after chick pea, grass pea, fababean and field pea precursor crops. The field experiments were conducted during 2014 main cropping season at Hawzien after chick pea and grass pea and at Emba Alaje after fababean and field pea precursor crops. The experiment consists of six nitrogen rates (0, 11.5, 23, 34.5, 46 and 69 kg Nha -1 ) laid in a RCBD with three replications. Phosphorus, sulfur and potassium fertilizers were also applied as basal for all plots at sowing. Surface soil samples were collected before planting and analyzed for selected soil properties. Soil analysis result of the experimental sites revealed that total nitrogen content (%) of the soil after chickpea-wheat (0.0695), grass pea-wheat (0.067), fababean-wheat (0.074) crop rotation were categorized under low range and after field pea-wheat (0.102) under medium range. Application of nitrogen had significantly increased grain and straw yield at Hawzien district after chick pea and grass pea precursor crops. At Emba-Alaje the highest grain yield was recorded on plots treated with 69 kg N ha -1 (6242 kg ha -1 ). Grain and straw yields of wheat increased up to a rate of 46 kg N ha -1 after fababean at Emba-Alaje district. There is no significant difference in grain and straw yields of wheat due to application of nitrogen after field pea crop rotation. In Hawzien the highest agronomic efficiency after chick pea and grass pea was recorded from plots treated with 46 kg N ha -1 and 34.5 kg N ha -1 , respectively. In Emba Alaje the highest agronomic efficiency after faba bean and field pea was recorded from plots treated with 11.5 kg N ha -1 and 23 kg N ha -1 , respectively. At Hawzien, the partial budget analysis revealed that application of 46 kg N ha -1 for bread wheat after chick pea and grass pea was economical with 1545% and 796 % marginal rate of return, respectively. At Emba Alaje, the partial budget analysis revealed that application of 34.5 kg N ha -1 for bread wheat after fababean was economical with 895% marginal rate of return. It could be concluded that application rate of N for wheat after leguminous crops should consider initial soil N and precursor crop.

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Response of bread wheat ( Tritcum aestivum L. ) to nitrogen after major leguminous crops rotation in Tigray, northern Ethiopia

Abstract The response of wheat to the application of different rates of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) under balanced fertilization on different soil types and agroecologies has not been well studied in Ethiopia. Therefore, the objectives of this study were to (1) determine soil-specific responses of wheat to N, P, K, and S under balanced fertilization; (2) quantify agroecology-specific N, P, K, and S response of wheat under balanced fertilization; and (3) determine nutrient use efficiency of wheat on different soil types under balanced fertilization. Trials were conducted on farmers’ fields across 24 locations covering 4 soil types and 5 agroecological zones (AEZs) from 2013 to 2017. The mean grain yields of wheat significantly varied with applied N and P fertilizer rates with soil types and AEZs. With balanced application of other nutrients, the optimum N rates for wheat were 138 kg N ha−1 on Cambisols and Luvisols, 92 kg N ha−1 on Vertisols, and 176 kg N ha−1 on Nitisols, while the optimum P rate was 20 kg P ha−1 on Cambisols and Vertisols. The nutrient dose–response curve did not reveal consistent pattern for K and S applications on all soil types. The agronomic efficiency of wheat decreased with increasing rates N and P on all soil types. The highest agronomic efficiency of N (15.8 kg grain kg−1 applied N) was recorded with application of 92 kg N ha−1 on Vertisols, while the highest agronomic efficiency of P (49 kg grain kg−1 applied P) was achieved with application of 10 kg P ha−1 on Cambisols. We conclude that applications of 92–138 kg N ha−1, 20 kg P ha−1, 18 kg K ha−1, and 10 kg S ha−1 under balanced application of zinc and boron could be recommended depending on soil type for wheat production in the study areas.

Balanced fertilization increases wheat yield response on different soils and agroecological zones in Ethiopia

This study was initiated to investigate the effect of nitrogen fertilizer on agronomic efficiency, yield and yield components of barley after faba bean precursor crop.  A field experiment was carried out in 2015 main cropping season at district at Ayba and Tek’a kebeles in Tigray Regional State, Ethiopia. The experiments were arranged in a randomized complete block design with three replications. Treatments were six levels of nitrogen (0, 11.5, 23, 34.5, 46 and 69 kg N ha-1). Soil samples were collected before planting and analyzed for selected physicochemical properties. Pre-planting soil analysis results revealed that total N was low at Tek’a kebelle (0.09%) and medium at Ayba (0.186%). The organic carbon content of experimental fields was medium at Ayba and low at Tek'a. Application of nitrogen had significantly influenced yield and yield components of barley at Tek'a site but not at Ayba after fababean precursor crop. This is consistent with the initial soil nitrogen and contribution of the precursor crop for nitrogen fixation. The highest agronomic efficiency was recorded from the addition of 23 kg N ha-1 (31.52 kg kg-1) and 34.5 kg N ha-1 (31.44 kg kg-1) at Ayba kebelle and Tek’a, respectively. Both biological and partial budget analysis depicted that application of 34.5 kg N ha-1 was found to be economical. Therefore, application of nitrogen after legume crop should consider initial soil result..

	Key words: Barley, Fababean, nitrogen, crop rotation, agronomic efficiency.

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Mehretab Haileselassie

Papers

Effects of Mineral Nitrogen and Phosphorus Fertilizers on Yield and Nutrient Utilization of Bread Wheat (Tritcum aestivum) on the Sandy Soils of Hawzen District, Northern Ethiopia

Response of bread wheat ( Tritcum aestivum L. ) to nitrogen after major leguminous crops rotation in Tigray, northern Ethiopia

Balanced fertilization increases wheat yield response on different soils and agroecological zones in Ethiopia

Agronomic efficiency, yield and yield components of food barley response to nitrogen rates after fababean in Emba Alaje, Northern Ethiopia