Effects of Organic and Inorganic Fertilizer on Growth,Yield, and Juice Quality and Residual Effects on Ratoon Crops of Sugarcane

ABSTRACT

Field experiments were carried out for three consecutive years (2003–2006) at Bangladesh Sugarcane Research Institute farm soil on plant (first crop after planting) and subsequent two ratoon crops of sugarcane. The main objectives of the study were to assess the direct and residual effects of organic and inorganic fertilizer on growth, yield, and juice quality of plant and ratoon crops. The plant crop consisted of four treatments. After harvesting of plant crop to evaluate the residual effects on ratoon crop the plots were subdivided except the control plot. Thus, there were seven treatments in the ratoon crop. Application of recommended fertilizer [nitrogen (N₁₅₀), phosphorus (P₅₂), potassium (K₉₀), sulfur (S₃₅), and zinc (Zn₃) kg ha^{? 1}] singly or 25% less of it either with press mud or farmyard manure (FYM) at 15 t ha^{? 1} produced statistically identical yield ranged from 67.5 to 69.0 t ha^{? 1} in plant crop. In the ratoon experiment when the recommended fertilizer was applied alone or 25% less of its either with press mud or FYM at 15 or even 7.5 t ha^{? 1} again produced better yield; it ranged from 64.8 to 69.2 in first ratoon and 68.2 to 76.5 t ha^{? 1} in second ratoon crops. Results showed that N, P, K, and S content in leaf progressively decreased in ratoon crops over plant crop. Juice quality parameters viz. brix, pol, and purity % remained unchanged both in plant and ratoon crops. Furthermore, organic carbon (C), available N, P, K, and S were higher in post harvest soils that received inorganic fertilizer in combination with organic manure than control and inorganic fertilizer treated soil. It may be concluded that the application of 25% less of recommended fertilizer (N₁₁₂, P₄₀, K₆₈, S₂₆, and Zn_2.2.5 kg ha^{? 1}) either with press mud or FYM at 15 t ha^{? 1} was adequate for optimum yield of plant crop. Results also suggest that additional N (50% extra dosage) keeping all other fertilizers at the same level like plant crop i.e. N₁₆₈, P₄₀, K₆₈, S₂₆, and Zn_2.25 kg ha^{? 1} either with press mud or FYM at 7.5 t ha^{? 1} may be recommended for subsequent ratoon crops to obtain good yield without deterioration in soil fertility.     

ENHANCING NITROGEN USE EFFICIENCY BY COMBINATIONS OF NITROGEN APPLICATION AMOUNT AND TIME IN WHEAT

Nitrogen (N) is one of the most important impact factors on development and growth of wheat. In this study the effects of nitrogen use efficiency on quantity and quality of grains were studied by agronomic management of N fertilizers on spring wheat (Triticum aestivum L.) grown under field conditions for two years. The experiments were performed at 16 combinations of N application amount and time, including four levels of N at 0, 60, 120 and 180 kg N ha^?1 that were used as pre-plant fertilizers, sub-treated with four levels of the same N amount used as top-dress fertilizers. As a result, with an increase in total N fertilizers, grain yield increased in a cubic equitation, but partial factor productivity (PFP_N, kg grain yield per kg N applied) decreased exponentially. With total fertilizers, N content and accumulation in vegetative tissues and grains increased linearly, but N uptake efficiency (UtE_N, kg nutrient taken up per kg N applied) decreased exponentially. When N was over-applied (>360 kg N ha^?1 in this study), grain yield clearly declined, due to decrease in productivity from per unit N. The high N level (240～300 kg N ha^?1), the reasonable distribution between pre-plant and top dress from the same amount N fertilizer not only increased grain yield but also enhanced N use efficiency.     

Effects of Water Stress and Nitrogen Fertilizer on Multi-Cut Forage Pearl Millet Yield,Nitrogen, and Water Use Efficiency

Forage pearl millet (Pennisetum americanum var. Nutrifeed) is a new forage crop in Iran. A field experiment was conducted at the University of Tehran to evaluate the response of pearl millet to four nitrogen (N) levels (0, 75, 150, and 225 kg N ha^?1) and four irrigation regimes (40%, 60%, 80%, and 100% of available soil water abbreviated to I₄₀, I₆₀, I₈₀ and I₁₀₀, respectively) during 2006–2007. Total dry matter production reached a maximum of 24.4 and 23.5 t ha^?1at I₄₀ and I₆₀ at N₂₂₅, respectively. Nitrogen use efficiency decreased by adding more fertilizer and minimum nitrogen use efficiency was recorded at N₂₂₅ over all irrigation regimes. At N₂₂₅, water use efficiency reached the maximum of 3.57 and 4.10 kg m^?3 in I₈₀ and I₁₀₀, respectively. Pearl millet forage could be produced in the regions where water is scarce and additional N fertilizer could increase total dry matter and water use efficiency.     

Evaluation of Controlled-Release Fertilizers for Northeast Florida Chip Potato Production

ABSTRACT

Controlled-release fertilizers (CRF) were compared with ammonium nitrate (AN) in a potato (Solanum tuberosum L.) production study at the University of Florida farm in Hastings, FL, in 2002. Treatments were no nitrogen (No-N), AN, and nine CRFs at 146 kg ha^?1 N and 225 kg ha^?1 N. CRF7 (146 kg ha^?1 N) resulted in highest total and marketable yields at 33.7 MT ha^?1 and 29.4 MT ha^?1, respectively. Tubers from the AN (225 kg ha^?1 N) and CRF9 (225 kg ha^?1 N) treatments had the highest specific gravity at 1.073. Nitrogen removal efficiency was highest in plants in CRF1 (43.0%) and CRF7 (47.3%) plots. Both were significantly higher than AN-treated plants. At 39 days after planting, NO₃-N and NH₄-N concentrations in lysimeter water samples were significantly higher in AN treatments. Leaf tissue N concentrations were sufficient throughout the growing season in all treatments except No-N.     

Nutritive value of marketable heads and outer leaves of white head cabbage cultivated at different nitrogen rates

The effect of different nitrogen treatments (100–400?kg?N?ha^?1) on yield and quality of marketable cabbage heads and outer green leaves (waste fraction) of two cultivars of Brassica oleracea convar. capitata var. alba L. grown in two years field experiment was studied. During harvest, the marketable cabbage heads and the outer leaves (not adjacent leaves of cabbage) were removed; total and marketable yield of cabbage were evaluated as well as nutritive value was determined based on content of some components, that is, dry matter, ascorbic acid, soluble polyphenols, total flavonoids, nitrates, total nitrogen and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH). The study showed a significant effect of nitrogen fertilization on the total and marketable yield of the tested cultivars of cabbage. The weight of total cabbage heads was increasing according to higher nitrogen fertilization from 100 up 400?kg?N?ha^?1 for both cultivars. The outer leaves of cabbage characterized by a significantly higher nutritive value compared with marketable head, which is supported by several-fold higher content of total flavonoids, soluble polyphenols and over the 100% increase in ascorbic acid content. Although the outer green leaves of cabbage are discarded after harvesting, they possess high nutritive potential which can be practically used or transformed into an added value product.     

Identification of Minimum Data Set Under Balanced Fertilization for Sustainable Rice Production and Maintaining Soil Quality in Alluvial Soils of Eastern India

The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T₁-control (no fertilization), T₂-farmyard manure @ 5 t ha^?1, T₃-farmers practice (60:30:30 kg N:P₂O₅:K₂O ha^?1), T₄-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P₂O₅:K₂O ha^?1) for targeted grain yield of 4.0 t ha^?1, T₅-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P₂O₅:K₂O ha^?1) plus FYM (5 t ha^?1) for targeted grain yield of 4.0 t ha^?1 and T₆-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P₂O₅:K₂O ha^?1) for targeted rice grain yield of 5.0 t ha^?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha^?1 was achieved in T₄ and T₆ treatments with 1.59% (4.06 t ha^?1) and –3.40% (4.83 t ha^?1) deviations, respectively. T₄, T_5, and T₆ significantly increased crop growth, nutrient uptake, available P (P_a) and K (K_a) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T₃. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T₅ as compared to T₆. Highest soil quality index was found in T₅ (0.95) followed by T₆ (0.90) and, lowest was in T₁ (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > K_a (11.3%) > PSM (9.68%) > N_a (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.     

Effects of Conventional and Stabilized Urea Fertilizers on Soil Biological Status

Effects of stabilized urea fertilizers [Alzon 46 (A) and UREAstabil (US)] on soil microbiological and chemical parameters and also on grain yield, 1000-grain weight, and oil content were tested in a precise field study on Luvisol in 2010–2012. Winter rapeseed (Brassica napus L. cv. Californium) was fertilized both in autumn [45 kg nitrogen (N) ha^?1] and in spring (155 kg N ha^?1) with A [urea with DCD (dicyandiamide) plus pyrrodiazole (1,2,4-1H-triazole)], US {urea with NBPT [N-(n-butyl)-thiophosphoric acid triamide]}, and conventional N fertilizers (pure urea, calcium ammonium nitrate). Eleven parameters were used to evaluate the soil status: microbial biomass carbon (C; microwave method [MW]), dehydrogenase activity, arylsulfatase activity, available organic carbon, electroconductivity, C_org (MW method), and pH (in water, H₂O). None of the 11 parameters demonstrated significant difference between control, conventional N fertilizers, and stabilized urea fertilizers. The greatest yield significantly different from the control (zero kg N ha^?1; 2598 ± 881 kg ha^?1) was found for both stabilized urea fertilizers: A (200 kg N ha^?1; 3772 ± 759 kg ha^?1) and US (200 kg N ha^?1; 3764 ± 625 kg ha^?1). The control achieved the greatest oil content (46.0 ± 1.2%), which was significantly different from all N-fertilized variants, and also the greatest 1000-grain weight (5.62 ± 0.62 g).     

Eucalyptus biochar application enhances Ca uptake of upland rice,soil available P,exchangeable K,yield, and N use efficiency of sugarcane in a crop rotation system

It was hypothesized that the application of eucalyptus biochar enhances nutrient use efficiencies of simultaneously supplied fertilizer, as well as provides additional nutrients (i.e., Ca, P, and K), to support crop performance and residual effects on subsequent crops in a degraded sandy soil. To test this hypothesis, we conducted an on‐farm field experiment in the Khon Kaen province of Northeastern Thailand to assess the effects of different application rates of eucalyptus biochar in combination with mineral fertilizers to upland rice and a succeeding crop of sugarcane on a sandy soil. The field experiment consisted of three treatments: (1) no biochar; (2) 3.1 Mg ha^?1 biochar (10.4 kg N ha^?1, 3.1 kg P ha^?1, 11.0 kg K ha^?1, and 17.7 kg Ca ha^?1); (3) 6.2 Mg ha^?1 biochar (20.8 kg N ha^?1, 6.2 kg P ha^?1, 22.0 kg K ha^?1, and 35.4 kg Ca ha^?1). All treatments received the same recommended fertilizer rate (32 kg N ha^?1, 14 kg P ha^?1, and 16 kg K ha^?1 for upland rice; 119 kg N ha^?1, 21 kg P ha^?1, and 39 kg K ha^?1 for sugarcane). At crop harvests, yield and nutrient contents and nitrogen (N) use efficiency were determined, and soil chemical properties and pH₀ monitored. The eucalyptus biochar material increased soil Ca availability (117 ± 28 and 116 ± 7 mg kg^?1 with 3.1 and 6.2 Mg ha^?1 biochar application, respectively) compared to 71 ± 13 mg kg^?1 without biochar application, thus promoting Ca uptake and total plant biomass in upland rice. Moreover, the higher rate of eucalyptus biochar improved CEC, organic matter, available P, and exchangeable K at succeeding sugarcane harvest. Additionally, 6.2 Mg ha^?1 biochar significantly increased sugarcane yield (41%) and N uptake (70%), thus enhancing N use efficiency (118%) by higher P (96%) and K (128%) uptake, although the sugar content was not increased. Hence, the application rate of 6.2 Mg ha^?1 eucalyptus biochar could become a potential practice to enhance not only the nutrient status of crops and soils, but also crop productivity within an upland rice–sugarcane rotation system established on tropical low fertility sandy soils.     

Application of Wastewater Irrigation on Growth and Yield of Chilli Under Nitrogen and Phosphorus Fertilization

In the present study a pot experiment was carried out in 2009 where different nitrogen (N) and phosphorus (P) combinations with soil (N₀P₀, N₂₀P₃₀, N₂₀P₆₀, N₄₀P₃₀, and N₄₀P₆₀) were taken into pots. Nutritional growth and yield such as length, fresh and dry weight, leaf area, leaf number, pedicle length, fruit length, fruit number, and seed content were significant at P?≤?0.05. Evaluation of data reveals that plant growth parameters and yield of chilli significantly increased in wastewater treatment with 20 kg ha^?1 N and 30 kg ha^?1 P in comparison to groundwater treatments. It was also found that higher dose of fertilizers with wastewater decreases plant growth and development of Capsicum annuum L. Thus it was concluded that wastewater reuse as a source of nutrient may not only solves the problems of the more use of chemical fertilizers but also decreases the fresh water scarcity in agriculture land.     

Biochar and Sewage Sludge Application Increases Yield and Micronutrient Uptake in Rice (Oryza sativa L.)

A greenhouse experiment was conducted in the Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi (U.P.), India, during kharif 2013 to find out the effect of biochar and sewage sludge (SS) on growth, yield, and micronutrient uptake in rice crop. Nine treatments were employed using six different doses of biochar (2.5, 5.0, 7.5 10, 15, and 20 t ha^?1) amended with a fixed dose of SS (30 t ha^?1) and 50% recommended dose of nitrogen (50% RDN), i.e., 60 kg ha^?1. Other three treatments were absolute control (no fertilizers), 100% recommended dose of fertilizers (100% RDF) which was 120:60:60 kg ha^?1 as nitrogen (N): phosphorus pentoxide (P₂O₅):dipotassium oxide (K₂O), and 30 t ha^?1SS + 50% RDN. Experimental results showed a significant increase in yield of rice crop with increasing levels of biochar along with SS. Application of biochar at 20 t ha^?1 along with 30 t ha^?1SS increased grain yield to the extent of 2.5 times over absolute control (no fertilizers) and 8.5% over control (100% RDF). The uptake of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) (micronutrients) increased significantly with graded doses of biochar application from 2.5 to 20 t ha^?1 in the soil. The maximum micronutrient uptake and grain yield of rice were found in T₉ where 30 t ha^?1SS along with 20 t ha^?1 biochar was applied with only 50% RDN. The maximum availability of micronutrients in soil was found with 30 t ha^?1 of SS + 50% RDN (T₃) followed by conjoint application of 20 t ha^?1 of biochar and 30 t ha^?1 SS + 50% RDN (T₉).     

Effects of Nitrogen Fertilizer on Yield Quality and Nutrient Content in Broccoli

ABSTRACT

This study was conducted to determine the effects of nitrogen (N) doses on yield, quality, and nutrient content in broccoli heads. Treatments consisted of 0, 150, 300, 450, and 600 kg N ha^{? 1}. Nitrogen rates significantly increased yield, average weight of main and secondary heads, and the diameter in broccoli compared to control. The highest total yield (34631 kg ha^{? 1}) was obtained at 300 kg N ha^{? 1}. At harvest, the highest amount of the total N in broccoli heads was measured at 450 kg N ha^{? 1} application. Potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) content increased with increases in nitrogen treatments but, phosphorus (P), copper (Cu), manganese (Mn), boron (B), and sodium (Na) contents were not influenced. Also, removed nutrients by broccoli head were highest at 300 kg ha^{? 1}N rate.     

WHEAT RESPONSE TO FARM YARD MANURE AND NITROGEN FERTILIZATION UNDER MOISTURE STRESS CONDITIONS

Information on the combined use of organic and inorganic fertilizers on wheat (Triticum aestivum L.) productivity is lacking under moisture stress conditions of Northwest Pakistan. The present experiment was designed to ascertain the combined effect of organic and inorganic fertilizer management on rainfed wheat. Four levels of farm yard manure, FYM, (0, 10, 20, and 30 Mg FYM ha^?1) and nitrogen (0, 30, 60, 90, and 120 kg N ha^?1) were used. The experiment was conducted at the Agriculture Research Farm of NWFP Agricultural University Peshawar, Pakistan during crop season of 2003–04. The experiment was laid out in randomized complete block design with four replications. Plant height, productive tillers m^?2, grains spike^?1, grain yield, straw yield, and harvest index were significantly higher in plots which received 30 Mg FYM ha^?1. In the case of nitrogen (N) no distinctive differences between the effect of 90 and 120 kg ha^?1 was observed for most of the parameters. Nitrogen application at 90 kg ha^?1 had significantly higher; plant height, grains spike^?1, grain yield, straw yield, and harvest index as compared with the lower levels, i.e., 0, 30, and 60 kg N ha^?1 but were at par with 120 N kg ha^?1. Significantly higher numbers of productive tillers m^?2, grains spike^?1, grain yield, straw yield and harvest index were recorded with application of 30 Mg FYM ha^?1 + 90 kg N ha^?1. The present study suggested that application of 30 Mg FYM ha^?1 + 90 kg N ha^?1 are promising levels for higher production of wheat under moisture stress conditions. Further research work is needed to ascertain the effect of N above 90 kg ha^?1 under different moisture regimes.     

Die Rolle der mikrobiellen Biomasse und des mineralisch fixierten Ammoniums bei den Stickstoff-Transformationen in niedersächsischen Löß-Ackerböden unter Winter-Weizen. II. Umsetzung von 15N-markiertem Stickstoff

Significance of microbial biomass and mineral fixed ammonium with respect to the nitrogen transformations in loess soils of Niedersachsen during the growing season of winter wheat. II. ¹⁵N-turnover Field experiments 1988/89 on a fallow plot of the southern Niedersachsen loess area with straw application (δ 10 t · ha^?1, homogeneously incorporated by hand) yielded an increase in microbial biomass-N (N_mic) by 60 kg N · ha^?1 · 30 cm^?1 until March 1989 and further 40 kg N · ha^?1, till May which was almost completely remobilized until harvest. For a cropped plot (with winter wheat and 10 t · ha^?1 straw incorporation), N immobilization was of similar magnitude. Up to 18% of the applied ¹⁵N-fertilizer (185 kgN · ha^?1) were microbially immobilized. In contrast to 1988/89, no significant mass change of N_mic occurred in 1991 due to straw application (δ 10t · ha^?1). Variations in the amount of N_mic were nearly independent on the treatment (crop, with 140 kg fertilizer-N · ha^?1 or without N-fertilizer, respectively; fallow plot without fertilizer-N) within a range of 225-400 kg N · ha^?1 · 30 cm^?1. Directly after N-application (each 70 kg N · ha^?1 in March and in May), up to 100% of the fertilizer-N were assimilated by the microbes. Subsequently, remobilization of the immobilized nitrogen occurred within 2 (in March) or 6 weeks (in May), respectively. Simultaneously, organic soil-N was mineralized after each N-application and minerally fixed for us biggest part. Between March and June, the fixed NH₄+ decreased by about 112 kg · ha^?1 · 30 cm^?1.     

NUTRIENT BUDGETING UNDER COCONUT-BASED PATCHOULI FARMING SYSTEM ON HAPLUDALF

Coconut-based farming systems are the tradition of tropical and subtropical regions. But, using patchouli [Pogostemon cablin (Blanco)] as an intercrop under coconut is of comparatively recent adoption and no information is absolutely available on the possibility of improving the quality of patchouli through better nutrient supply. A field experiment was, therefore, carried out using different sources of organic manures (M₀–control, M₁–FYM farmyard manure 20 tonnes ha^?1, M₂–pig manure 10 tonnes ha^?1 and M₃–vermicompost 5 tonnes ha^?1) versus inorganic fertilizers (N_o–control, N₁ - 60 kg ha^?1, N₂–80 kg ha^?1, and N₃–100 kg ha^?1) within the interspaces of the coconut plantation on soil taxonomically classified as Orchic Hapludalf under humid tropics of northeast India. Application of treatment M₃ alone produced maximum biomass of leaves (11.24 tonnes ha^?1) followed by M₂ (10.82 tonnes ha^?1), and M₁ (9.54 tonnes ha^?1), all of which were significantly (P < 0.05) superior over M₀ (7.54 tonnes ha^?1). Among the various levels of nitrogen (N), maximum biomass yield of leaves was observed with N₃ (11.63 tonnes ha^?1) ≥ N₂ (11.64 tonnes ha^?1), followed by N₁(8.96 tonnes ha^?1) with the highest yield (19.97 tonnes ha^?1) registered through the combination of M₃N₃. Treatment combination M₃N₃ in turn maintained higher fungal (118 × 10² vs. 31 × 10² with M₀N₀ c.f.u.g^?1 soil) and bacterial populations (48 × 10⁵ vs. 31 × 10³ with M₀N₀ c.f.u.g^?1 soil) for better nutrient acquisition through improvements in the concentration of soil available nutrients. These responses consequently improved the oil concentration in leaves (3.65% with M₃N₃ vs. 2.40% with M₀N₀) and alcohol (49.90% with M₃N₃ vs. 44.52% in M₀N₀) as quality indices. This research verified that the quality of patchouli leaves as an intercrop was raised, besides improving coconut yield (40–55 nuts palm^?1) as main crop, when utilizing combined treatments of vermicompost enriched with inorganic N under coconut-patchouli farming systems.     

INTEGRATED NUTRIENT MANAGEMENT FOR CABBAGE-BRINJAL-RED AMARANTH CROPPING PATTERN IN HOMESTEAD AREA

An experiment was conducted to study the effect of organic manure and chemical fertilizers on soil properties and vegetable crops in the cabbage-brinjal-red amaranth cropping pattern at the homestead in a Grey Terrace Soil (Aric Albaquept) of Bangladesh. There were eight treatments: poultry manure (PM) at 5 t ha^?1, cowdung (CD) at 10 t ha^?1, household waste (HW) at 10 t ha^?1, PM at 2.5 t ha^?1 + chemical fertilizers (CF), CD at 5 t ha^?1 + CF, HW at 5 t ha^?1 + CF, CF, and Control. The lone CF treatment indicates 100% chemical fertilizers and any manure + CF indicates supplementary or reduced rate of fertilizers. The PM at 2.5 t ha^?1 + CF treatment performed the best yield for cabbage and brinjal, and HW at 5 t ha^?1 + CF yielded the highest for red amaranth. The highest uptake of nitrogen, phosphorus, potassium, and sulfur was also found in the treatment that produced the highest yield. Bulk density, organic carbon, and nutrient availability in soil as determined after two-crop cycles were improved due to the applications of manure.     

Importance of soil mineral N in early spring and subsequent net N mineralisation for winter wheat following winter oilseed rape and peas in a milder climate

Abstract

Nine biennial field experiments, 2000–2004, in south Sweden, 55–56°N, with winter wheat following winter oilseed rape, peas, and oats, were used to estimate the impact of a future milder climate on winter wheat production in central Sweden, 58–60°N. The trials included studies 1) on losses during winter of soil mineral nitrogen (N_min, 0–90 cm soil), accumulated after the preceding crops in late autumn, 2) on soil N mineralisation (N_net) during the growing season of the wheat (early spring to ripeness) and 3) on grain yield and optimum N fertilisation (Opt-N rate) of the wheat. Average N_min in late autumn following winter oilseed rape, peas, and oats was 68, 64, and 45 kg ha^?1, respectively, but decreased until early spring. Increased future losses of N_min during the winter in central Sweden due to no or very short periods with soil frost should enhance the demand for fertiliser N and reduce the better residual N effect of winter oilseed rape and peas, compared with oats. Their better N effect will then mainly depend on larger N_net (from March to maturity during the winter wheat year). Owing to more plant-available soil N (mainly as N_net) Opt-N rates were lower after oilseed rape and peas than after oats despite increased wheat yields (700 kg ha^?1) at optimum N fertilisation. In addition to these break crop effects, a milder climate should increase winter wheat yields in central Sweden by 2000–3000 kg ha^?1 and require about 30–45 kg ha^?1 more fertiliser N at optimum N fertilisation than the present yield levels. Increased losses and higher N fertilisation to the subsequent winter wheat in future indicates a need for an estimation of the residual N effect at the individual sites, rather than using mean values as at present, to increase N efficiency.     

Modulation in growth,development, and yield of Camelina sativa by nitrogen application under water stress conditions

Camelina sativa has rejuvenated as a successful oilseed crop in the recent years. It is a low-input-requiring crop with an unusual fatty acid composition. A pot experiment was conducted in rain-out shelter to investigate the effect of different nitrogen levels (N₀ = 0, N₁ = 50, N₂ = 100, and N₃ = 150 kg ha^?1) on the growth and yield of two C. sativa genotypes (Australian and Canadian) under normal [100% field capacity (FC)] and water stressed (60% FC) conditions. The experiment was laid out in a completely randomized design with factorial arrangement having three replicates in the Department of Crop Physiology, University of Agriculture, Faisalabad. The results indicated that nitrogen doses and water stress levels significantly affected the growth and yield of C. sativa. Maximum values for growth indices like leaf area index (LAI), crop growth rate (CGR), leaf area duration (LAD), net assimilation rate (NAR), and yield attributes were observed under N₂ treatment (100 kg ha^?1) followed by the treatment in which nitrogen was applied at the rate of 50 kg ha^?1. However, growth and yield components significantly reduced under water stress conditions (60% FC). Of both the genotypes, Australian Camelina performed better as compared to Canadian Camelina under both non-stress and drought stress conditions.     

Developing nitrogen management strategies under drip fertigation for wheat and maize production in the North China Plain based on a 3‐year field experiment

The intensive winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) cropping systems in the North China Plain (NCP) rely on the heavy use of mineral nitrogen (N) fertilizers. As the fertigated area of wheat and maize in the NCP has grown rapidly during recent years, developing N management strategies is required for sustainable wheat and maize production. Field experiments were conducted in Hebei Province during three consecutive growth seasons in 2012–2015 to assess the influence of different N fertigation rates on N uptake, yield, and nitrogen use efficiency [NUE: recovery efficiency (RE_N) and agronomic efficiency (AE_N)]. Five levels of N application, 0 (FN₀), 40 (FN_40%), 70 (FN_70%), 100 (FN_100%), and 130% (FN_130%) of the farmer practice rate (FP: 250 kg N ha^?1 and 205.5 kg N ha^?1 for wheat and maize, respectively), corresponding to 0, 182.2, 318.9, 455.5, and 592.2 kg N ha^?1 y^?1, respectively, were tested. Nitrogen in the form of urea was dissolved in irrigation water and split into six and four applications for wheat and maize, respectively. In addition, the treatment “drip irrigation + 100% N conventional broadcasting” (DN_100%) was also conducted. All treatments were arranged in a randomized complete block design with three replications. The results revealed the significant influence of both N fertigation rate and N application method on grain yield and NUE. Compared to DN_100%, FN_100% significantly increased the 3‐year averaged N recovery efficiency (RE_N) by 0.09 kg kg^?1 and 0.04 kg kg^?1, and the 3‐year averaged N agronomic efficiency (AE_N) by 2.43 kg kg^?1 and 1.62 kg kg^?1 for wheat and maize, respectively. Among N fertigation rates, there was no significant increase in grain yield in response to N applied at a greater rate than 70% of FP due to excess N accumulation in vegetative tissues. Compared to FN_70%, FN_100%, and FN_130%, FN_40% increased the RE_N by 0.17–0.57 kg kg^?1 and 0.03–0.34 kg kg^?1and the AE_N by 4.60–27.56 kg kg^?1 and 2.40–10.62 kg kg^?1 for wheat and maize, respectively. Based on a linear‐response relationship between the N fertigation rate and grain yield over three rotational periods it can be concluded that recommended N rates under drip fertigation with optimum split applications can be reduced to 46% (114.6 kg N ha^?1) and 58% (116.6 kg N ha^?1) of FP for wheat and maize, respectively, without negatively affecting grain yield, thereby increasing NUE.     

Root Growth and Soil Water Dynamics in Relation to Inorganic and Organic Fertilization in Maize–Wheat

Agricultural productivity is increasingly becoming dependent upon soil fertility, which is generally thought to be supplemented through the application of nutrients mainly through inorganic fertilizers. The present study aims to characterize the soil physical environment in relation to long-term application of farmyard manure (FYM) and inorganic fertilizers in a maize–wheat cropping system. The treatments in both the maize and wheat systems included a control (without any fertilizer or FYM), FYM (farmyard manure at 20 t ha^?1), N₁₀₀ (nitrogen at 100 kg ha^?1), N₁₀₀P₅₀ (nitrogen and phosphorus at 100 and 50 kg ha^?1), and N₁₀₀P₅₀K₅₀ (nitrogen, phosphorus, and potash at 100, 50, and 50 kg ha^?1). The treatments were replicated four times in a randomized complete block design in sandy loam soil. The root mass density in surface layers of both the crops was lower in FYM and higher in inorganic fertilizer plots. The root length density was found to be highest in FYM-treated plots and lowest in control plots. The periodic soil matric suction during wheat following maize remained highest in FYM plots followed by that in N₁₀₀ plots in all the layers. The soil water storage of wheat at harvest (rice–wheat) was highest (21.1 cm) in control and lowest (17.8 cm) in FYM-treated plots. The soil water status, root growth, and crop performance improved with balanced fertilization.     

Long-term nitrogen balance for pearl millet (Pennisetum glaucum L.) in an acid sandy soil of Niger

On acid sandy soils of Niger (West Africa) fertilizer N recovery by pearl millet (Pennisetum glaucum L.) is often more than 100 per cent in years with normal or above average rainfall. Biological nitrogen fixation (BNF) by N₂-fixing bacteria may contribute to the N supply in pearl millet cropping systems. For a long-term field experiment comprising treatments with and without mineral fertilizer (F) and with and without crop residue application (CR) a N balance sheet was calculated over a period of six years (1983-1988). After six years of successive millet cropping total N uptake (36-77 kg N ha^?1 yr^?1) was distinctly higher than the amount of fertilizer N applied (30 kg N ha^?1 yr^?1). The atmospheric input of NH₄-N and NO₃-N in the rainwater was about 2 kg N ha_?1 yr^?1, 70 % in the form of NH₄-N. Gaseous NH₃ losses from urea (broadcast, incorporated) were estimated from other experiments to amount to 36 % of the fertilizer N applied. Nitrogen losses by leaching (15 to > 25 kg N ha^?1 yr^?1) were dependent on the treatment and on the quantity and distribution of single rainfall events (>50 mm). Decline in total soil N content (0-60 cm) ranged from 15 to 48 kg N ha^?1 yr^?1. The long-term N balance (1983-1988) indicated an annual net gain between 6 (+CR-F) and 13 (+CR+F) kg N ha^?1 yr^?1. For the control (-CR-F) the long-term N balance was negative (10 kg N ha^?1 yr^?1). In the treatment with crop residues only, the N balance was mainly determined by leaching losses, whereas in treatments with mineral fertilizer application the N balance depended primarily on N removal by the millet crop. The annual net gain in the N balance increased from 7 kg ha^?1 with mineral fertilizer to 13 kg ha^?1 in the combination mineral fertilizer plus crop residues. In both the rhizosphere and the bulk soil (0-15 cm), between 9 and 45% of the total bacterial population were N₂-fixing (diazotrophic) bacteria. The increased N gain upon crop residue application was positively correlated with an increase in the number of diazotrophic and total bacteria. The data on bacterial numbers suggest that the gain of N in the longterm N balance is most likely due to an N input by biological nitrogen fixation. In addition, evidence exists from related studies that the proliferation of diazotrophs and total bacteria in the rhizosphere due to crop residue application stimulated root growth of pearl millet, and thus improved the phosphorus (P) acquisition in the P deficient soil.