INTEGRATED EFFECT OF INORGANIC AND ORGANIC NITROGEN SOURCES ON SOIL FERTILITY AND PRODUCTIVITY OF MAIZE

The present study was designed to assess the effect of organic materials, i.e., farm yard manure (FYM), poultry manure (PM) and sugar cane filter cake (FC) along with mineral nitrogen on yield and soil organic fertility. Our results indicated that among sole nitrogen (N) sources, highest grain yield was recorded from poultry manure. In the case of integrated N sources, maximum grain yield was obtained from 25% poultry manure + 75% mineral N source. Grain ear^?1 and 1000 grain weight was highest with the application of poultry manure among sole N sources. Highest grain ear^?1 and 1000 grain weight was observed from 25% poultry manure + 75% mineral N source. Application of poultry manure as sole N sources resulted maximum increase in soil total N and organic matter when compared with other sole N sources. Among N sources applied in different proportion, maximum total soil N was recorded from 25% poultry manure + 75% mineral N. We concluded from these experiments that integrated application of N sources in different proportion greatly improves the N economy and enhance crop productivity in low N soils.     

Enhancing Soil Fertility and Wheat Productivity through Integrated Nitrogen Management

An experiment was conducted to investigate the effects of integrated nitrogen (N) management on soil fertility and crop productivity. Application of N sources in different proportions significantly (P ≤ 0.05) enhanced soil total N, organic matter, grain N uptake, straw N uptake, and grain yield. Maximum grain yield, total soil N (%), and organic matter (%) were recorded from the treatment of poultry manure as compared with other sole N sources. Among integrated application of N sources, 25% poultry manure + 75% mineral N source produced the greatest grain yield. Maximum total soil N and organic matter were observed in the combined application of 75% poultry manure + 25% mineral N. Maximum grain N and straw N uptake was recorded from the treatment applied with farmyard manure as sole N source. However, among integrated application of N sources, 25% poultry manure + 75% mineral N source resulted in the greatest grain N and straw N uptake.     

Organic manure supplementation effects on rice–pulse cropping system productivity

The effects of organic manure supplementation on rice–pulse cropping system productivity were studied. Three pulses, viz., blackgram, greengram and pea were grown after rice on the same plots to explore the feasibility of growing second crops with carry-over residual soil moisture and residual soil fertility. The study revealed that during the rainy season, 30%–35% higher rice grain yield was obtained when both inorganic and organic sources of nutrients were applied compared with the full dose of inorganic fertilizer, and the rice grain yield was 65%–78% higher than obtained following farmers’ practices. In the post-rainy season, pea crop recorded the highest grain yield of 490 kg ha^-1 under the treatment combination of Sesbania and inorganic fertilizer. Organic carbon, and available N, P, K also enhanced yield by 20%–29%, 5.0%–29.4% to 7.9%–39.9% and 22.4%–60.3%, respectively when 25% N was applied through different organic sources of nutrients (green manure/press mud/farmyard manure).     

Productivity,nutrient uptake and post-harvest soil fertility as influenced by cotton-based cropping system with integrated nutrient management practices in semi-arid tropics

Field experiments were conducted on cotton to evaluate the different cotton-based intercropping system along with balanced nutrient management practices on enhancing cotton productivity. Cropping systems have been considered as main plots and nutrient management practices have been considered as subplots. The results showed that cotton + onion system recorded the highest cotton equivalent yield (CEY) of 2052 and 1895 kg ha^?1 which was on par with cotton intercropped with dhaincha, which recorded 2010 and 1894 kg of CEY ha^?1 in both the seasons. Combined application of 100% recommended NPK with bioinoculants (S₅) registered highest CEY in both the seasons. Cotton intercropped with dhaincha (M₂) recorded highest uptake of N, P, and K. Among the nutrient management practices, application of 100% recommended NPK with bioinoculants (S₅) showed highest uptake of N, P, and K. A similar trend was noticed in the post-harvest soil fertility too and it is significantly higher under cotton + dhaincha and application of 100% recommended NPK with bioinoculants treatment compared to 100% recommend NPK alone. It could be concluded from these results that crop productivity can be improved and soil fertility status can be sustained with integrated plant nutrient management practices.     

Effects of Transgenic Cotton-Based Cropping Systems and Their Fertility Levels on Succeeding Wheat Crop

Cotton–wheat is the second most important cropping system after rice–wheat in India and Pakistan, and is practiced on about 4.02 mha. By 2010, more than 6 million Indian farmers had adopted transgenic Bt cotton on 9.4 mha—almost 90% of the country’s total cotton area. There is a paucity of information on the effects of intercropping and integrated nitrogen (N)–management practices in transgenic Bt cotton on productivity, nutrient availability, and soil biological properties in the succeeding wheat crop in a cotton–wheat system. A study was made to evaluate and quantify the residual effect of two-tiered intercropping of cotton and groundnut with substitution of 25–50% recommended dose of nitrogen (RDN) of cotton by farmyard manure (FYM) on productivity and soil fertility in a cotton–wheat system at New Delhi during 2006–2008. Wheat following groundnut-intercropped cotton receiving 50% RDN substitution through FYM had significantly 5% greater grain yield than that after sole cotton. Residual soil fertility in terms of organic carbon (C), potassium permanganate (KMnO₄)-N, and dehydrogenase activity (14%) showed an improvement under cotton + groundnut–wheat system with substitution of 50% RDN of cotton by FYM. Apparent N balance as well as actual change in KMnO₄-N at wheat harvest was negative in most of the treatments, with greater loss (–58.1) noticed under pure stand of the cotton–wheat system with 100% RDN of cotton through urea. The study suggested that inclusion of legume and organic manure in transgenic Bt-cotton–wheat system is a sustainable practice for combating escalating prices of N fertilizers with environmental issues and instability of transgenic hybrids in south Asian countries.     

不同棉花间作模式中作物养分吸收和利用对间作优势的贡献

棉花间作能够解决棉花与粮食作物和蔬菜作物争地的矛盾,但是否有间作优势以及间作优势的作物营养基础是众所关心的问题。本研究在新疆石河子大学试验站设置棉花与花生、大豆、鹰嘴豆、洋葱、萝卜、线辣椒间作以及各个作物单作的田间试验,以期揭示以棉花为基础的间作体系的间作优势以及养分吸收和利用效率对间作优势的贡献。结果表明,棉花与鹰嘴豆、花生、洋葱、萝卜间作体系作物的吸氮量明显高于单作18%~74%,棉花与大豆和线辣椒间作体系作物的吸氮量低于单作10%和34%;棉花与大豆、鹰嘴豆、花生、洋葱、萝卜间作体系中作物吸磷量比单作增加5%~104%,棉花与线辣椒间作体系作物的吸磷量低于单作6%;棉花与花生、洋葱、萝卜间作体系中作物吸钾量高于单作20%~58%,棉花与大豆、鹰嘴豆和线辣椒间作作物吸钾量低于间作19%~22%。棉花与鹰嘴豆、花生、洋葱、萝卜间作以后土地当量比(LER)分别为1.02、1.30、1.12、1.68,都大于1,说明具有间作优势;棉花与大豆、线辣椒间作后LER分别为0.91和0.99,小于1,没有间作优势。棉花与花生、洋葱和萝卜间作体系氮磷钾吸收效率对LER的贡献分别为0.41~0.82、0.25~1.04和0.15~0.59,利用效率的贡献分别为0.35~0.04、0.03~0.14和0.16~0.01。结果表明,棉花与其他作物的间作优势在营养方面的基础主要来自于间作相对于单作吸收效率的增加,而不是利用效率的改变。     

Effects of Fertilizers on Yield,Sustainability, and Soil Fertility under Rainfed Pigeon pea + Rice System in Subhumid Oxisol Soils

A long-term field experiment was conducted at the research farm of the All-India Coordinated Research Project for Dryland Agriculture, Phulbani, Orissa, India, from 2001 to 2006 to identify the best integrated nutrient-use treatments for ensuring greater productivity, profitability, sustainability, and improved soil quality in pigeon pea + rice (two rows of pigeon pea followed by five rows of rice alternately) intercropping system. In all, nine treatments, eight comprising integrated nutrient-use practices, chemical fertilizer (CF), farmyard manure (FYM), and green leaf manure (GLM) to supply nitrogen (N) at 45 kg N ha^–1 and one farmer's practice equivalent to 25 kg N ha^–1 (FYM 5 t ha^–1), were tested on a long-term basis. Results of the study revealed that 20 kg N ha^–1 (FYM) + 25 kg N (CF) gave maximum mean rice grain yield of 1.52 t ha^–1, followed by 20 kg N (GLM) + 25 kg N (urea) with grain yield of 1.51 t ha^–1. In the case of pigeon pea, 30 kg N (FYM) +15 kg N (urea) gave maximum pigeon pea grain yield of 0.94 t ha^–1, which was 34% greater than the sole application of chemical fertilizer. Pigeon pea grain yield tended to increase with increasing proportion of organic N in FYM + CF or GLM + CF combinations. Application of 20 kg N (FYM) + 25 kg N (urea) recorded maximum mean rice equivalent yield of 3.59 t ha^–1 and sustainability yield index of 59%. While studying profitability, application of 20 kg N (FYM) + 25 kg N (CF) gave maximum net returns of US$168.94 ha^–1. Impact of treatments on soil quality as assessed in terms of relative soil quality indices (RSQI) increased with increasing proportion of organic sources of N. Using an innovative and new approach, an index of integrated productivity–sustainability–profitability–soil quality performance index (I _P,S,Pr,SQ) was computed to make a precise evaluation of the treatments. Based on this index, the order of performance of the treatments was T₆ [20 N (FYM) + 25 N (CF)] (7.7) > T₇ [30 N (FYM) + 15 N (CF) (6.9)] > T₃ [20 N (GL) + 25 N (CF)] (6.8) > T₅ [10 N (FYM) + 35 N (CF) (6.6)] > T₉ [GL] (6.5) > T₈ [CF] (6.2) > T₄ [30 N (GL) + 15 N (CF)] (6.0) > T₂ [10 N (GL) + 35 N (CF)] (5.7) > T₁ [FYM at 5 t ha^–1] (4.1). Thus, the results and the methodology adopted in this study using long-term data would be very useful to researchers, farmers, land managers, and other stakeholders not only in India but also across the world under similar climatic and edaphic situations.     

Substituting urea by organic wastes for improving maize yield in alkaline soil

Abstract

Nitrogen (N) deficiency is a very common problem of alkaline soils. Incorporation of organic residues with urea could be promising practice for improving soil properties and crop yield. This study was aimed, to evaluate the responses of two maize cultivar (Azam and Jalal) to organic wastes and Urea (sole organic residues i.e. seed cake (SC), poultry manure (PM), press mud (PrM) and mineral nitrogen (urea) and their combinations with urea (25%, 50% or 75%) applied at 150?kg N ha^?1 under field conditions. Significant differences were recorded for leaf area index, plant height, number of grains ear^?1, 1000 grain weight, biological and grain yield to N sources. Maize cultivar Jalal performed significantly better than Azam for all tested traits. The performance of both cultivars was significantly better when N was applied as either SC/PM with urea at 25:75, SC and PM with urea at 25:25:50, 100% sole urea, SC/PrM with urea at 50:50, or all organic N sources (25%) with urea (75%). Integration of organic wastes with urea gave the higher maize yield however, it was similar to the yield obtained from sole urea but due to allied environmental and health hazards, the sole use of urea could not be encouraged.     

Performance of Turmeric and Soil Moisture Depletion Pattern Under Different Water Regimes and Nutrient Sources at New Alluvial Zone of Indo-Gangetic Plains,India

In India, the production of turmeric is not even half compared to its potential. To analyze the possibilities for higher production in turmeric, this study was conducted at the BCKV, Gayeshpur, West Bengal, during 2011 and 2012, to evaluate the effect of irrigation scheduling (0.6, 0.9, and 1.2 irrigation water (IW)/cumulative pan evaporation (CPE) and rainfed) in main plots and nutrient management [100% inorganic, 75% inorganic + 25% FYM (Farm yard manure), and 50% inorganic + 25% FYM + 25% vermicompost] in subplots on soil moisture depletion and productivity of turmeric. The highest value of fresh rhizome yield (23.90 kg ha^?1) and qualitative indices were obtained with irrigation schedule at 0.9 IW/CPE ratio water regimes and 50% inorganic + 25% FYM + 25% vermicompost. The correlation coefficients of water use and yield of turmeric were found at 0.943. The combination of 0.9 IW/CPE and 50% inorganic + 25% FYM + 25% vermicompost improved the overall performance of turmeric crop.     

Effect of Soil and Nutrient-Management Treatments on Soil Quality Indices under Cotton-Based Production System in Rainfed Semi-arid Tropical Vertisol

Rainfed semi-arid tropical Vertisols of the Indian subcontinent encounter many problems on account of the physical, chemical, and biological soil qualities and consequently have poor crop yields. To ensure sustainable crop production, there is a need to improve and periodically assess the quality of these soils by adopting suitable soil and nutrient-management practices on a long-term basis. Hence, soil quality assessment studies were conducted at the Central Research Institute for Dryland Agriculture, Hyderabad, India, by adopting an ongoing long-term experiment from Akola Centre (Maharashtra) of All-India Coordinated Research Project for Dryland Agriculture (AICRPDA) for the rainfed Vertisol. This long-term experiment was initiated in 1987 with six soil and nutrient management treatments: T1, control; T2, 50 kg nitrogen (N) + 25 kg phosphorus pentoxide (P₂O₅) ha^?1; T3, 25 kg N ha^?1 through leuceana; T4, 25 kg N ha^?1 through farmyard manure (FYM); T5, 25 kg N + 25 kg P₂O₅ + 25 kg N ha^?1 through FYM; and T6, 25 kg P₂O₅ ha^?1 + 50 kg N ha^?1 through leuceana under cotton + greengram intercropping (1:1). Out of the 19 soil quality parameters studied, significant influence of the soil and nutrient-management treatments was observed on almost all the parameters except exchangeable calcium (Ca), available iron (Fe), labile carbon (LC), and bulk density (BD). A standard methodology using principal component analysis (PCA) and linear scoring technique (LST) was adopted to identify the key indicators and for computation of soil quality indices. The various key soil quality indicators identified for these Vertisols under cotton + green gram system were pH, electrical conductivity (EC), organic carbon (OC), available K, exchangeable magnesium (Mg), dehydrogenase assay (DHA), and microbial biomass carbon (MBC). The soil quality indices as influenced by different long-term soil and nutrient-management treatments varied from 1.46 to 2.10. Among the treatments, the conjunctive use of 25 kg P₂O₅ ha^?1 + 50 kg N ha^?1 through leuceana green biomass (T6) maintained significantly higher soil quality index with a value of 2.10 followed by use of 25 kg N + 25 kg P₂O₅ + 25 kg N ha^?1 through FYM (T5) (2.01). The order of percent contribution of these identified indicators to soil quality indices was OC (28%) > MBC (25%) > available K (24%) > EC (7%) > pH (6%) = DHA (6%) > exchangeable Mg (4%). Thus, the findings of the present study could be of immense use to the researchers, land managers, farmers, nongovernment organizations (NGOs) and other stakeholders for making periodical assessment of key indicators of soil quality, identifying the best soil and nutrient-management treatments and practices, and planning for improving soil quality to achieve higher productivity goals on a sustainable basis in rainfed semi-arid tropical Vertisol regions. The methodology of the study could also be useful for other rainfed semi-arid tropical Vertisol regions of the world.     

Integrated Fertilizer Management: Influence on Soil Nitrogen,Available Phosphorus,Potassium, Nutrient Uptake and Maize Yield

A field experiment was conducted on an Alfisol (kandic paleustalf) in Abeokuta, Southwestern Nigeria, for two seasons to assess the influence of inorganic and organic fertilizers on nitrogen (N), phosphorus (P), potassium (K), nutrient uptake and maize yield. The treatments consisted of three rates of organic fertilizer 0, 5 and 10 t ha^?1 in the form of poultry manure and NPK fertilizer (20:10:10) applied at 0 and 120 kg ha^?1. Maize (Zea mays) was used as the test crop. The results showed that the combined application of 10 t ha^?1 poultry manure and 120 kg ha^?1 NPK fertilizer enhanced the uptake of N, P and K better than other treatment combinations. Application of 10 t ha^?1 poultry manure alone gave the highest grain yield, which was 67.02% higher than the control in the first season. Complementary application of 5 t ha^?1 poultry manure with 120 kg ha^?1 NPK 20–10-10 was recommended for grain yield.     

Effects of Long-Term Fertilizer Application and Rainfall Distribution on Cotton Productivity,Profitability, and Soil Fertility in a Semi-arid Vertisol

Long-term fertilizer experiments were conducted on cotton (Gossypium hirsutum) for 21 years with eight fertilizer treatments in a fixed site during 1987–2007 to identify an efficient treatment to ensure maximum yield, greater sustainability, monetary returns, rainwater-use efficiency, and soil fertility over years. The results indicated that the yield was significantly influenced by fertilizer treatments in all years except 1987 1988, and 1994. The mean cotton yield ranged from 492 kg ha^?1 under the control to 805 kg ha^?1 under 25 kg nitrogen (N) [farmyard manure (FYM)] + 25 kg N (urea) + 25 kg phosphorus (P) ha^?1. Among the nutrients, soil N buildup was observed with all treatments, whereas application of 25 kg N + 12.5 kg P ha^?1 exhibited increase in P status. Interestingly, depletion of potassium (K) was recorded under all the fertilizer treatments as there was no K application in any of the treatments. An increase in soil N and P increased the plant N and P uptake respectively. Using relationships of different variables, principal component (PC) analysis technique was used for assessing the efficiency of treatments. In all the treatments, five PCs were found significant that explained the variability in the data of variables. The PC model of 25 kg N (FYM) + 25 kg N (urea) + 25 kg P ha^?1 explained maximum variability of 79.6% compared to other treatments. The treatment-wise PC scores were determined and used in developing yield prediction models and measurement of sustainability yield index (SYI). The SYI ranged from 44.4% in control to 72.7% in 25 kg N (FYM) + 25 kg N (urea) + 25 kg P ha^?1, which attained a mean cotton yield of 805 kg ha^?1 over years. Application of 25 kg N (FYM) + 25 kg N (urea) + 25 kg P ha^?1 was significantly superior in recording maximum rainwater-use efficiency (1.13 kg ha^?1 mm^?1) and SYI (30.5%). This treatment also gave maximum gross returns of Rs. 30272 ha^?1 with benefit–cost ratio of 1.60 and maintained maximum organic carbon and available N, P, and K in soil over years. These findings are extendable to cotton grown under similar soil and agroclimatic conditions in any part of the world.     

Effects of organic fertilizers on yam productivity and some soil properties of a nutrient-depleted tropical Alfisol

Field experiments were conducted at Owo, southwest Nigeria to select organic fertilizer treatments most suitable for sustaining high soil fertility and yam productivity on a nutrient-depleted tropical Alfisol. Eight organic fertilizer treatments were applied at 20 t ha^?1 with a reference treatment inorganic fertilizer (NPK 15–15–15) at 400 kg ha^?1 and natural soil fertility (control), laid out in a randomized complete block design with three replications. Results showed that organic fertilizers significantly increased (p = 0.05) tuber weight and growth of yam, soil and leaf N, P, K, Ca and Mg, soil pH and organic C concentrations compared with the NSF (control). The oil palm bunch ash + poultry manure treatment increased tuber weight, vine length, number of leaves and leaf area of yam by 66, 25, 21 and 52%, respectively, compared with inorganic fertilizer (NPK) and 37, 22, 19 and 44%, respectively, compared with poultry manure alone. Sole or mixed forms of organic fertilizers showed significant improvement in soil physical conditions compared with IF (NPK) and NSF (control). Synergistic use of oil palm bunch ash + poultry manure at 10 t ha^?1 each was most effective for sustainable management of soils and for improving agronomic productivity of yam.     

Assessment of nitrogen fertilization in cotton/soybean intercropping using the 15N isotope dilution method

Intercropping of cotton and legume plants offers long-term crop productivity while saving agricultural resources and improving soil health. However, the use of nitrogen (N) in cotton/legume intercropping systems requires further evaluation. In this study, three N fertilization rates (cotton/soybean: 160/20, 320/40 and 480/80 kg N ha⁻¹) incorporating three root barrier systems (complete, semi and no root barrier between the crops) under cotton/soybean intercropping systems were conducted to assess interactions between N supply and N transfer, recovery and residue using the ¹⁵N isotope dilution method. The results show that cotton was a stronger competitor for N than soybean plants. The 320/40 kg N ha⁻¹ treatment with no root barrier system inhibited the growth of soybean, while the growth, productivity and N uptake for cotton were maximized. The N fixation rate (%NDFA) in soybean and N transfer rate (%NTFS) from soybean to cotton decreased with the increasing N fertilizer application rate, whereas the intercropping system with no root barrier increased %NDFA and %NTFS. The higher N fertilization rate increased the N residue on the side of cotton, whereas the intercropping with no root barrier increased N utilization rate (%NUR) and reduced N residue rate (%NRR). The N transfer amount (NTA) was positively correlated with cotton yield, dry matter (DM) and N uptake, while NTA was negatively correlated with these indicators for soybean. Overall, cotton/soybean intercropping adapted to the 320/40 kg N ha⁻¹ condition and intercropping with no root barrier system by balancing growth, changing N uptake and regulating N fixation transfer, mitigating the issue of N residue.     

Yield,Nutrient Uptake,and Quality of Stevia as Affected by Organic Sources of Nutrient

A field experiment was conducted during 2008 and 2009 at the Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, India, to study the effect of organic sources of nutrient on yield, nutrient uptake, fertility status of soil, and quality of stevia crop in the western Himalayan region. The experiment comprised eight different combinations of organic manure [farmyard manure (FYM), vermicompost (VC), and apple pomace manure (AP)]. Total leaf dry biomass increased by 149% over the control with application of VC 1.5 t ha^?1 + AP 5 t ha^?1. Application of organic manures enhanced organic carbon and available nutrient status of soil more than the control. Nitrogen (N) and phosphorus (P) content in stem were significantly affected by the application of organic manures over the control. Stevia plants supplied with FYM 10 t ha^?1 + AP 2.5 t ha^?1 recorded more total glycoside than other treatments. Stevioside yield (kg ha^?1) was greater with application of FYM 10 t ha^?1 + AP 2.5 t ha^?1.     

Impact of Animal Manure on Soil Chemistry,Mineral Nutrients,Yield, and Fruit Quality in ‘Golden Delicious’ Apple

ABSTRACT

Incorporating deep litter cow and deep litter poultry manures with the top 30-cm soil improved orchard soil chemistry, including nutrient availability, soil organic matter, electrical conductivity (EC), pH, cation exchange capacity (CEC) and biological activity in a ‘Golden Delicious’ apple (Malus domestica Bork) orchard in Zanjan, Iran. Application of deep litter cow manure at 30 t ha^?1 or deep litter poultry manure at 10 t ha^?1 resulted in a higher rate of nitrogen (N) release, and thus increased yield and fruit size, but decreased fruit color. The least leaf minerals were found in the untreated control trees. The control trees showed minor symptoms of N, iron (Fe), and magnesium (Mg) deficiencies during the following season. Positive correlation existed between the rate of manure applied and the content of soil organic matter (OM). The deep litter poultry manure at 10 t ha^?1 increased the soil K, Mg, calcium (Ca), ammonium-N, and EC levels.     

Effects of different organic materials on forage yield and nutrient uptake of silage maize (Zea mays L.)

The use of organic materials as a source of nutrients on agricultural lands ameliorates soil physical properties as well as being an environmentally friendly way of disposing of their wastes. This study was conducted to determine effects of three organic materials (poultry litter, cattle manure, leonardite) on yield and nutrient uptake of silage maize. Poultry litter and cattle manure were applied based on phosphorus (P) or nitrogen (N) requirements of the crop whereas leonardite was applied only one dose (500 kg ha^?1) and also combined with three inorganic fertilizer doses (100%, 75%, 50% of recommended inorganic fertilizer dose). According to the results, the highest green herbage yield and nutrient uptake values were observed in LEO-100 whereas N-based treatments significantly decreased yield and nutrient uptake of silage maize. The use of organic materials as a combination with inorganic fertilizer in silage maize cultivation is highly beneficial for sustainable forage production.     

Effective Nutrient Sources for Plant Growth on Bauxite Residue

We conducted a field experiment to evaluate alternatives to poultry manure, the normal fertilizer used for growing dust control crops and native vegetation on bauxite residue sand. We compared plant growth, nutrient uptake and residue properties after applications of poultry manure, compost, composted poultry manure and inorganic fertilizer. The compost used was prepared from green waste treated with piggery waste. Plant growth was poor under the compost and composted poultry manure treatments, which produced 0.69 and 1.11 t ha^{? 1} of above ground biomass, respectively. This compared with 2.43 t ha^{? 1} from the inorganic fertilizer treatment which had a similar biomass to the poultry manure treatment (3.00 t ha^{? 1}). All treatments, including poultry manure, had low foliar concentrations of some nutrients, with low levels of N, P, K, Mg, Cu and Zn found in most treatments. Of the two treatments which gave effective dust control (inorganic fertilizer and poultry manure) the most economical was inorganic fertilizer which cost A$1227 ha^{? 1}. The high application rate of the poultry manure made it the most expensive fertilizer treatment at a cost of A$1650 ha^{? 1}. There appeared to be no long-term benefit of using organic amendments, as organic fertilizers did not improve residue conditions (organic matter content, pH, electrical conductivity, activity of Na⁺ ions) compared with the inorganic fertilizer. It was concluded that inorganic fertilizer could provide a suitable, cost-effective alternative to poultry manure for growth of dust control crops, with further research required to address low levels of some nutrients.     

Alterations in yield,physicochemical components and mineral composition of onion following organic manure and inorganic nitrogen application

Onion is the one of the most important vegetable crops grown extensively throughout the world; hence, understanding the response of the crop to the form and amount of N provided is of immense importance. In a field experiment, poultry and cattle manure (at 10?t/ha) were compared with four inorganic nitrogen (N) application levels (0, 60, 90 and 120?kg?N/ha), and six combinations of manure and N applications were investigated. Plant growth and total yield (kg/ha) significantly increased, when N application increased from 0 to 120?kg/ha, with or without added poultry manure. Plant height, leaf number and neck thickness were significantly reduced at 0?kg/ha?N plus cattle manure. The bulb ascorbic acid concentration significantly increased with the use of poultry manure (15.94?mg/100?g) and cattle manure (15.94?mg/100?g), compared with 120?kg/ha inorganic N (11.42?mg/100?g). No significant effects were observed on total phenolics and total soluble solids of onion bulbs following the different fertiliser treatments. Cattle manure increased P and K concentrations, whilst poultry manure significantly increased Zn and Fe concentrations in onion bulbs. Onion bulb Ca and Mg concentrations were lower when cattle manure (0.19% and 0.12%) was used than when other organic or inorganic fertilisers were used. Therefore, organic manure increases the concentrations of certain minerals in onions, compared with inorganic N application, without negatively affecting bulb size.     

Dry Matter,Nitrogen, Phosphorous,and Potassium Partitioning,Accumulation, and Use Efficiency in Transgenic Cotton-Based Cropping Systems

A better understanding of the fate of nutrients in transgenic cotton (Gossypium hirsutum L.) fields will improve nutrient efficiencies, will optimize crop growth and development, and may help to enhance soil quality. A study was made to evaluate and quantify the effect of cropping system [sole cotton and groundnut (Arachis hypogaea) intercropping with transgenic cotton] and nitrogen (N) management [control (0N), 100% recommended dose of nitrogen (RDN) through urea, substitution of 25% RDN through farmyard manure (FYM), and substitution of 50% RDN through FYM] on dry matter (DM) and nutrient partitioning and accumulation by transgenic cotton and groundnut at New Delhi during 2006–2007. Soil and plant samples were collected and analyzed at 60, 90, and 120 days after sowing and at harvest. Results revealed that intercropping of groundnut with cotton did not significantly affect DM and nutrient partitioning in cotton, but residual soil fertility in terms of potassium permanganate (KMnO₄) N showed an improvement in contrast to Olsen's P and ammonium acetate (NH₄OAc)–exchangeable K over sole cotton. At harvest, of total DM assimilated, leaves constituted 10–20%, stem 50%, and reproductive parts of cotton accounted for the rest. For each kilogram of seed cotton produced, the crop assimilated 61 g of N, of which 23 g was partitioned to harvested seed cotton. Substitution of 25% RDN through FYM, being on par with 100% RDN through urea, recorded greater DM, nutrient uptake in different parts of cotton, agronomic N-use efficiency (9.5 kg seed cotton kg N^?1), and apparent N recovery (83.3%) over 50% RDN substitution through FYM and control. The control, being on par with 50% RDN substitution through FYM, recorded significantly greater DM and nutrient uptake by intercropped groundnut over other treatments. Apparent N and potassium (K) balance at the end of study was negative in all treatments; however, the actual change in KMnO₄ N was positive in all the treatments except control. Our study suggests that intercropping of groundnut with transgenic cotton and substitution of 25% dose of N through FYM is sustainable in tropical countries.