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1.
Besides being an essential macronutrient for plant growth, potassium (K) also acts as a stress-relieving agent against various biotic and abiotic stresses, especially water stress. An experiment consisting of three lowland Thai rice varieties (Pathumthani 1, RD57, RD41), two cultivation methods [dry direct seeding (DDS), transplanting (TP)] and four K doses (0, 80, 120,160?kg ha?1) under alternate wetting and drying (AWD) water regime was conducted to investigate the impact of K and cultivation method on lowland rice varieties subjected to AWD. Pathumthani 1 had significantly higher grain yield at the 120?kg K ha?1 compared with all other K doses. RD57 and RD41 had maximum grain yield at the 80 and 120?kg K ha?1, respectively, which was significantly higher than the control; however, grain yield among different K doses was mostly similar for RD57 and RD41. K application at the rate of 120?kg ha?1 for Pathumthani 1 and 80?kg ha?1 for RD57 and RD41 could be a feasible option. The performance of DDS and TP was better at the 80 and 120?kg K ha?1, respectively. Application of K at the optimum dose with proper selection of variety and cultivation method could help in sustainable rice production.  相似文献   

2.
Productivity of rainfed finger millet in semiarid tropical Alfisols is predominantly constrained by erratic rainfall, limited soil moisture, low soil fertility, and less fertilizer use by the poor farmers. In order to identify the efficient nutrient use treatment for ensuring higher yield, higher sustainability, and improved soil fertility, long term field experiments were conducted during 1984 to 2008 in a permanent site under rainfed semi-arid tropical Alfisol at Bangalore in Southern India. The experiment had two blocks—Farm Yard Manure (FYM) and Maize Residue (MR) with 5 fertilizer treatments, namely: control, FYM at 10 t ha?1, FYM at 10 t ha?1 + 50% NPK [nitrogen (N), phosphorus (P), potassium (K)], FYM at 10 t ha?1 + 100% NPK (50 kg N + 50 kg P + 25 kg K ha?1) and 100% NPK in FYM block; and control, MR at 5 t ha?1, MR at 5 t ha?1 + 50% NPK, MR at 5 t ha?1 + 100% NPK and 100% NPK in MR block. The treatments differed significantly from each other at p < 0.01 level of probability in influencing finger millet grain yield, soil N, P, and K in different years. Application of FYM at 10 t ha?1 + 100% NPK gave a significantly higher yield ranging from 1821 to 4552 kg ha?1 with a mean of 3167 kg ha?1 and variation of 22.7%, while application of maize residue at 5 t ha?1 + 100% NPK gave a yield of 593 to 4591 kg ha?1 with a mean of 2518 kg ha?1 and variation of 39.3% over years. In FYM block, FYM at 10 t ha?1 + 100% NPK gave a significantly higher organic carbon (0.45%), available N (204 kg ha?1), available P (68.6 kg ha?1), and available K (107 kg ha?1) over years. In maize residue block, application of MR at 5 t ha?1 + 100% NPK gave a significantly higher organic carbon (0.39%), available soil N (190 kg ha?1), available soil P (47.5 kg ha?1), and available soil K (86 kg ha?1). The regression model (1) of yield as a function of seasonal rainfall, organic carbon, and soil P and K nutrients gave a predictability in the range of 0.19 under FYM at 10 t ha?1 to 0.51 under 100% NPK in FYM block compared to 0.30 under 100% NPK to 0.67 under MR at 5 t ha?1 application in MR block. The regression model (2) of yield as a function of seasonal rainfall, soil N, P, and K nutrients gave a predictability in the range of 0.11 under FYM at 10 t ha?1 to 0.52 under 100% NPK in FYM block compared to 0.18 under MR at 5 t ha?1 + 50% NPK to 0.60 under MR at 5 t ha?1 application in MR block. An assessment of yield sustainability under different crop seasonal rainfall situations indicated that FYM at 10 t ha?1 + 100% NPK was efficient in FYM block with a maximum Sustainability Yield Index (SYI) of 41.4% in <500 mm, 64.7% in 500–750 mm, 60.2% in 750–1000 mm and 60.4% in 1000–1250 mm rainfall, while MR at 5 t ha?1 + 100% NPK was efficient with SYI of 29.6% in <500 mm, 50.2% in 500–750 mm, 40.6% in 750–1000 mm, and 39.7% in 1000–1250 mm rainfall in semi-arid Alfisols. Thus, the results obtained from these long term studies incurring huge expenditure provide very good conjunctive nutrient use options with good conformity for different rainfall situations of rainfed semiarid tropical Alfisol soils for ensuring higher finger millet yield, maintaining higher SYI, and maintaining improved soil fertility.  相似文献   

3.
ABSTRACT

Root system is an important factor for crop productivity under water- and nutrient-limited environments. A pot study was conducted to evaluate root system response of three Thai rice varieties (Pathumthani 1, RD57, RD41) under three cultivation methods (dry direct seeding [DDS], wet direct seeding [WDS], transplanting [TP]) and three levels of alternate wetting and drying irrigation (–5, –15, –30 kPa). A second pot experiment examined the effect of potassium (K) rates (0, 80, 120, 160 kg ha–1) on root system response of the same varieties under DDS and TP subjected to alternate wetting and drying at –5 kPa. Pathumthani 1 was more tolerant to moisture stress; RD57 and RD41 showed an inconsistent response to moisture-deficit conditions. Rice plant under TP was more sensitive to moisture stress; rice plant performed better under DDS even at the highest soil moisture stress of –30 kPa. K application at the rate of 120 kg ha–1 as basal under DDS was optimum for root system development of Pathumthani 1, while RD57 and RD41 had higher actual root length at the same K rate regardless of cultivation methods. Alternate wetting and drying up to –30 kPa could be safely applied for the three tested varieties. The performance of root system of Pathumthani 1 was better under DDS method of cultivation. K fertilization at 120 kg ha–1 can be recommended as optimum rate under water-saving cultivation techniques for the three tested varieties.  相似文献   

4.
A study was conducted to assess fertilizer effect on pearl millet–wheat yield and plant-soil nutrients with the following treatments: T1, control; T2, 100% nitrogen (N); T3, 100% nitrogen and phosphorus (NP); T4, 100% nitrogen, phosphorus and potassium (NPK); T5, 100% NPK + zinc sulfate (ZnSO4) at 25 kg ha?1; T6, 100% NPK + farmyard manure (FYM) at 10 t ha?1; T7, 100% NPK+ verimcompost (VC) at 2.5 tha?1; T8, 100% NPK + sulfur (S) at 25 kg ha?1; T9, FYM at 10 t ha?1; T10, VC at 2.5 t ha?1; T11, 100% NPK + FYM at 10 t ha?1 + 25 kg S ha?1 + ZnSO4 at 25 kg ha?1; and T12, 150% NPK treatments. Treatments differed significantly in influencing soil-plant nutrients and grain and straw yields of both crops. Grain yield had significant correlation with soil-plant N, P, K, S, and zinc (Zn) nutrients. The study indicated superiority of T11 for attaining maximum pearl millet grain yield (2885 kg ha?1) and straw yield (7185 kg ha?1); amounts of N (48.9 kg ha?1), P (8.8 kg ha?1), K (26.3 kg ha?1), S (20.6 kg ha?1), and Zn (0.09 kg ha?1) taken up; and amounts of soil N (187.7 kg ha?1), P (13.7 kg ha?1), K (242.5 kg ha?1), S (10.1 kg ha?1), and Zn (0.70 kg ha?1). It was superior for wheat with grain yield (5215 kg ha?1) and straw yield (7220 kg ha?1); amounts of N (120.7 kg ha?1), P (13.8 kg ha?1), K (30 kg ha?1), S (14.6 kg ha?1), and Zn (0.18 kg ha?1) taken up; and maintaining soil N (185.7 kg ha?1), P (14.5 kg ha?1), K (250.5 kg ha?1), S (10.6 kg ha?1), and Zn (0.73 kg ha?1). Based on the study, 100% NPK + FYM at 10 tha?1 + Zn at 25 kg ha?1 + S at 25 kg ha?1 could be recommended for attaining maximum returns of pearl millet–wheat under semi-arid Inceptisols.  相似文献   

5.
Impacts of 43-year nutrient management on carbon (C) and nutrient dynamics were studied in a rice-wheat-jute system in tropical India. Carbon dynamics was investigated on the basis of its distribution of labile (microbial biomass C, permanganate oxidizable C and water soluble C) and slow pools (Walkley Black oxidizable organic C), its indices (C pool index, lability index) and C management index (CMI) at different soil depths. Nutrient dynamics was judged by major nutrients availability, and related soil enzymatic activities. We studied seven treatments including unfertilized control, 100% NPK (N:P2O5:K2O 60:30:60), 50% NPK, 150% NPK, 100% NP, 100% N, 100% NPK + farm yard manure (10 tonnes FYM ha?1). Nutrients availability and soil enzymatic activities were significantly increased under balanced fertilization (100% NPK + FYM) over other treatments. Labile, slow and total C was also found highest in 100% NPK + FYM. Enhanced C indices under 100% NPK + FYM over 100% NPK and other treatments signified the importance of long term balanced fertilization on soil C stabilization. Lability indexes were lower at sub-soil (30-45cm). In terms of favourable nutrient dynamics and CMI, balanced application of NPK plus organics were recommend for long term sustainability of rice-wheat-jute system in tropics.  相似文献   

6.
Effects of continuous cropping and addition of organic manures (farmyard manure, FYM, and groundnut shells, GNS) along with inorganic fertilizers on nonexchangeable potassium (K) release kinetics in a K-deficient Alfisol were studied in a 20-year manurial experiment under arid conditions. There was a depletion in available K under continuous cropping without K input (control) as compared to other treatments such as 100% nitrogen–phosphorus–potassium (NPK), 50% NPK + 4 metric tons (MT) groundnut shells ha?1, 50% NPK + 4 MT FYM ha?1, and 100% organic (i.e., 5 MT FYM ha?1). Over 20 years of cropping without K input, available K was reduced from 155 kg ha?1 (in 1985) to 82 kg ha?1 (in 2005), showing a negative balance of 73 kg ha?1. Soil in control plots showed available K in the deficient range (<50 mg kg?1), whereas four other fertilizer and manurial treatments were greater than the critical limit. Considerable improvements in nonexchangeable K-release parameters such as step K and cumulative K release were observed in manured plots over control. Parabolic diffusion and first-order kinetic equations explained K release from soils. Potassium-release rates were drastically reduced in control plots, and there were increased release rates with continuous addition of manures. Results suggest that soils with groundnut shells or FYM (4 MT ha?1) along with 50% inorganic fertilizer additions could maintain greater K release rates after 20 years of cropping as compared to cropping without K input.  相似文献   

7.
The field study was conducted in April 2006 in a long-term fertilization experiment that was set up in 1983. The aims of this study are to compare the weediness in plots with nitrogen–phosphorus–potassium (NPK), NPK + farmyard manure (FYM), and NPK + stalk treatments and to study the effect of increasing N doses on the weeds and winter wheat plants. The bifactorial test was arranged in a split-plot design with three replications. The treatments were the following: 0, 50, 100, 150, and 200 kg ha?1 N, 100 kg ha?1 phosphorus pentoxide (P2O5), and 100 kg ha?1 potassium oxide (K2O). Three weed species were dominant in the experiment: Veronica hederifolia, Consolida regalis, and Stellaria media. The NPK treatment resulted in the smallest average weed cover. The significantly greatest weed cover was found on the plots treated with NPK + FYM, but the greatest biomass production of winter wheat was measured also in the NPK + FYM treatment, which resulted in a good crop competition. The weed cover was increased proportionally by the rising N doses. The effect of increasing N rates was positive on the winter wheat biomass and on wheat competition to the weeds. Results of our study show that we can manage weeds better using favorable plant nutrition.  相似文献   

8.
ABSTRACT

Soil acidity is one of the main limitations for optimal use of land resources for better crop production. And, long-term fertilization experiments found to be helpful in increasing the nutrient supply in these acidic soils. Keeping this in view, a field experiment on rice was carried out by applying biofertilizers and enriched compost in an acidic Inceptisol of Assam over 10 successive years (2006–15) to examine its effects on nutrient availability and soil enzymatic activity. This experiment had five treatments viz. absolute control (T1), 100% recommended doses (RD) of inorganic NPK (T2), 50% RD of inorganic NP + 100% K +biofertilizers (T3), 50% RD of inorganic NP + 100% K +1 tonne enriched compost ha?1 (T4) and 25% RD of inorganic NP + 100% K +2 tonnes enriched compost ha?1 (T5) under randomized block design with four replications. After completing 10 years of experiment, it was observed that integrated use of enriched compost and biofertilizers with reduced doses of inorganic fertilizers enhanced the soil enzymatic activity as well as nutrient availability in rice grown in acidic clay loam soils of Assam. Application of biofertilizers and enriched compost had positive impact on plant accessible nitrogen, phosphorus and potassium in soil as compared to inorganic fertilizers. Also soil organic matter content increased considerably by these treatment. Integrated nutrient management practice in rice had also significantly enhanced the dehydrogenase, fluorescein diacetate and phospho-monoesterase activity in soil.  相似文献   

9.
The present investigation was carried out to evaluate the effect of integrated nutrient management (INM) on crop yield sustainability and soil quality in a long-term trial initiated during the wet season of 1971 under a humid subtropical climate. Over 41 years of study, 100% nitrogen, phosphorus, and potassium (NPK) + farm yard manure (FYM) at 15 t ha?1 recorded the most sustainable grain yields. Optimal and superoptimal NPK fertilizers gave quite similar crop yields to that of 100% NPK + FYM at 15 t ha–1 up to two decades but thereafter yields declined sharply due to emergence of zinc (Zn) deficiency. The sustainable yield index (SYI) values indicated that wheat yields were more sustainable than rice. Soil organic carbon and available N, P, K, and Zn in the control plot decreased the most, whereas 100% NPK + FYM at 15 t ha–1 improved available N, P and K, maintained soil organic carbon, and decreased Zn over initial levels. Grain yield and SYI were more significantly correlated with Soil Organic Carbon (SOC). Continuous application of FYM contributed the maximum Soil Quality Index (SQI) (0.94), followed by Zn.  相似文献   

10.
Effect of integrated use of mycorrhiza, lime, inorganic fertilizers, and organic manures on microbial activities and yield performance of yam bean (Pachyrhizus erosus L.) was studied for two consecutive kharif (rainy) seasons during 2013–14 and 2014–15 in an acid Alfisol. The experiment was laid out with 16 treatments consisting of graded doses of soil test–based nitrogen, phosphors, and potassium (NPK); lime; mycorrhiza; organic sources, that is, farmyard manure (FYM), vermicompost, and green manure; secondary magnesium sulfate (MgSO4) and micronutrients zinc sulfate (ZnSO4 and borax). Significantly highest mean tuber yield (29.61 t ha?1) was recorded due to integrated application of lime + FYM + NPK + ZnSO4. Graded doses of NPK showed a mean yield response of 65%, 134%, and 191% due to addition of 50%, 100%, and 150% of NPK over control, respectively. Inoculation of vesicular–arbuscular mycorrhiza (VAM) combined with NPK and FYM recorded a mean tuber yield of 25.14 t ha?1. Highest mean dry matter (18.85%) was recorded due to application of 150% NPK, whereas highest starch content on fresh weight basis was recorded due to integrated use of lime + FYM + NPK + MgSO4 (11.11%). Application of 150% NPK has recorded highest dehydrogenase activity (2.018 µg TPF h?1 g?1) and fluorescein diacetate hydrolysis assay (2.012 µg g?1 h?1). Fungal inoculation of VAM in combination with lime + FYM + NPK recorded highest acid and alkaline phosphatase activities (82.20 and 67.02 µg PNP g?1 soil h?1, respectively). Soil biological activities and phosphatase activities had highly significant relationship with tuber yield and biochemical constituents of yam bean. The study emphasized the conjunctive use of soil test–based inorganic fertilizers, lime, and organic manures to enhance the enzymatic activities and to realize higher crop yields of yam bean in acid Alfisols.  相似文献   

11.
Based on a long-term finger millet-groundnut rotation study conducted for 24-years during 1992–2015 under Alfisols at Bangalore, organic and inorganic fertilizer effects on soil organic carbon (SOC) sequestration and sustainability of yield were assessed. Field experiments were conducted with T1:Control; T2:FYM@ 10t ha?1; T3:FYM@ 10t ha?1 + 50% NPK; T4:FYM@ 10t ha?1 + 100% NPK, and T5:100% recommended NPK in same plot every year. T5 comprised of 50 kg N, 50 kg P2O5 and 25 kg K2O ha?1 for finger millet and 25 kg N, 50 kg P2O5 and 25 kg K2O ha?1 for groundnut. Sustainability yield index of treatments was assessed using measurements made on variability of yield over years. The amount of carbon sequestered was assessed to identify a superior treatment for improving soil quality. Balanced use of 100% NPK+ FYM for maintenance of SOC at antecedent level with biomass-C of 1.62 Mg C ha?1 year?1 was feasible for sustaining production under semi-arid Alfisols.  相似文献   

12.
Carbon sequestration potential (CSP) and sustainability of gardenpea-french bean cropping system was assessed with farmyard manure (FYM) application vis-à-vis mineral fertilization as recommended NPK (NPK) and integrated nutrient management practices (INM) after six years’ cropping in Indian Himalayas. Application of 20 tons FYM ha?1 provided highest CSP (0.527 Mg C ha?1 year?1) in soil and sustainability index. With the help of quadratic equations, it was estimated that maximum profit (optimum yield) and turn over of invested money could be achieved with application of 20.0 and 15.6 t FYM ha?1, respectively. Application of 5.9 and 8.9 tons FYM ha?1 would substitute NPK and INM, respectively. Pod number plant?1 was the most important yield-contributing attribute as found from principal component analysis. Pod yield could be modelled through multiple linear equation with help of yield attributes.  相似文献   

13.
The aim of this study was to understand impacts of long-term (43 years) fertilization on soil aggregation, N accumulation rates and δ15N in surface and deep layers in an Alfisol. Soil samples from seven treatments were analysed for N stocks, aggregate-associated N in 0–30 cm and the changes in δ15N in 0–90 cm depths. The treatments were: unfertilized control (control); recommended N dose (N); recommended N and phosphorus doses (NP); recommended N, P and potassium doses (NPK); 150% of recommended N, P and K doses (150% NPK); NPK + 10 Mg FYM ha?1 (NPK + FYM) and NPK + 0.4 Mg lime ha?1 (NPK + L). Results revealed that plots under NPK + FYM had ~39% higher total N concentrations than NPK + L in 0–30 cm soil layers. In NPK + L, macro-aggregates had 35 and 11% and microaggregates had 20 and 9% lower δ15N values than NPK + FYM in 0–15 and 15–30 cm soil layers, respectively. However, plots receiving NPK + FYM had ~39% greater deep soil (30–90 cm) N accumulation than NPK + L. These results would help understanding N supplying capacity by long-term fertilization and assist devising N management strategies in sub-tropical acidic Alfisols.  相似文献   

14.
The experiment on the effect of primary biomethanated spentwash (PBSW) on soil properties, nutrient uptake and yield of wheat on sodic soil was carried out at a research farm of Post Graduate Institute, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra state, India, during the post-monsoon season. The experimental soil was sodic calcareous having Sawargaon series of isohyperthermic family of Vertic Haplustepts. The experiment was laid out in a randomized block design with nine treatments and three replications. The treatments consisted of varying doses of PBSW (100, 200, 300, 400 and 500 m3 ha?1), absolute control, farmyard manure (FYM) 5 t ha?1 + RDF-AST (recommended dose of fertilizer as per soil test), FYM 5 t ha?1 + 50% GR (gypsum requirement) + RDF-AST and FYM 5 t ha?1 + 100% GR + RDF-AST. The results revealed that the physical properties, namely bulk density and hydraulic conductivity, were improved in sodic soil due to the application of increased doses of PBSW. A significant reduction in pH, calcium carbonate and exchangeable sodium percentage (ESP) and an increase in organic carbon, cation-exchange capacity (CEC) and electrical conductivity (EC) were observed in the soil, due to the addition of PBSW. The available soil nitrogen (N), phosphorus (P), potassium (K) and micronutrient iron, manganese, copper and zinc (Fe, Mn, Cu and Zn) content after the harvest of wheat was the highest in the 500 m3 ha?1 treatment compared with all the other treatments. The exchangeable calcium (Ca2+), magnesium (Mg2+) increased significantly and exchangeable Sodium (Na+) reduced significantly with increased doses of PBSW. The saturation paste extract analysis also showed the same trend. A significant increase in the EC of the saturation paste of extract of the soil was observed in all PBSW treatments and it was the highest (4.75 dS m?1) in PBSW application @ 500 m3 ha?1. The application of PBSW @ 500, 400, 300 and 200 m3 ha?1 resembled the treatments of FYM + gypsum @ 100 GR + RDF-AST, FYM + gypsum @ 50 GR + RDF-AST and FYM + RDF-AST, respectively, regarding the biological properties of sodic soil. The PBSW application @ 500 m3 ha?1 had recorded the highest grain (47.33 q ha?1) and straw (72.72 q ha?1) yield and the maximum total uptake of N, P, K, Fe, Mn, Cu, and Zn by wheat, which was at par with the treatment of FYM (5 t ha?1) + gypsum @ 100% GR + RDF-AST.  相似文献   

15.
This present investigation took place on a continuing long-term fertilizer experiment, initiated in 1972 at the experimental farm of the College of Agriculture CSK HPKV, Palampur, aimed at studying nutrient dynamics of micronutrients, especially Zn, after continuous use of chemical fertilizers and amendments over the previous 36 years in an acid Alfisol under a maize–wheat system. Treatments investigated were as follows: T1: Control; 100% N; 100% NP; 100% NPK (optimal application - 120:26:33(maize)/25(wheat)); 100% NPK + FYM (10 t ha−1 to the maize crop); T6: 100% NPK + lime (900 kg ha−1); T7: 100% NPK + Zn (25 kg ha−1 as ZnSO4); T8: 100% NPK + Hand weeding; T9: 100% NPK (-S); T10: 150% NPK (super-optimal application); and T11: 50% NPK (sub-optimal application). Different forms of zinc in soil were determined through a sequential extraction method. Results revealed that previous applications of high-analysis fertilizers and amendments caused a marked depletion in the pools of Zn as compared to buffer plots. All pools of Zn as well as crop productivity and Zn uptake were noticeably greater in farmyard manure (FYM)-amended plots compared with plots not receiving fertilizer. The residual fraction was the dominant form but organically bound and exchangeable forms were found to play major role in nutrient supply, crop productivity and nutrient uptake. Correlation and regression analysis studies showed that organic forms constituted the most important pool contributing towards variation in yield and uptake by maize and wheat crops. Exchangeable and organically bound forms contributed significantly towards the availability of DTPA-extractable Zn in soil.  相似文献   

16.
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.  相似文献   

17.
We investigated some aspects of soil quality and community-level physiological profiles (CLPP) of bacteria in soil under a long-term (37 years) trial with either exclusive inorganic fertilizers or fertilizers combined with farmyard manure cultivated with jute–rice–wheat system. The treatments consisted of 100% recommended dose (RD) of NPK, 150% RD of NPK, 100% RD of N, 100% RD of NPK + FYM (10 t ha−1 year−1), and untreated control. Long-term application of 150% RD of NPK lowered the soil pH considerably while the soils in the other treatments remained near neutral. The 100% RD of NPK + FYM treated plot showed significantly highest accumulation of organic carbon, total nitrogen, microbial biomass carbon, basal soil respiration, and fluorescein diacetate hydrolyzing activity among the treatments. CLPP analysis in Biolog Ecoplates revealed that utilization of carbohydrates was enhanced in all input treated regimes, while the same for polymers, carboxylic acids, amino acids, and amines/amides were similar or less than the untreated control. However, within these groups of carbon sources, heterogeneity of individual substrate utilization between treatments was also noted. Taken together, addition of organic supplements showed significantly increased microbial biomass carbon and microbial activity, but input of nutrient supplements, both inorganic and organic, only marginally affected the overall substrate utilization pattern of soil microorganisms.  相似文献   

18.
In the present study, seven fertilizer treatments [T1, 50% NPK; T2, 100% NPK (Recommended dose of fertilizer, 200–65.4–124.5 kg N-P-K ha?1); T3, 150% NPK; T4, 100% PK; T5, 100% NK; T6, 100% NP and T7, control (zero NPK)] with four replications were assessed in the new alluvial soil zone (Entisols) of West Bengal, India. The objectives of the study were to generate information on potato productivity, profitability, indigenous nutrient supply and net gain/loss of NPK in post-harvest soil. Plants grown under higher NPK supply resulted in higher tuber yield and there were significant (p ≤ 0.05) reductions in total yield with nutrient omissions. Nutrient?limited yields were 19.78, 2.83 and 1.77 t ha?1 for N, P and K, considering total tuber yield (28.24 t ha?1) obtained under 100% NPK as targeted yield. Indigenous nutrient supply of N, P and K were estimated at 24.1, 22.34 and 110.22 kg ha?1, respectively that indicates higher K?supplying capacity of experimental soil as compared to N and P. Net income (US$1349 ha?1 year?1) and B:C ratio (1.91) was highest with 100% NPK, and further addition of NPK (150%) resulted in decrease on net return (US$1193 ha?1 year?1) and B:C ratio (1.73).  相似文献   

19.
A long‐term fertilizer experiment, over 27 years, studied the effect of mineral fertilizers and organic manures on potassium (K) balances and K release properties in maize‐wheat‐cowpea (fodder) cropping system on a Typic Ustochrept. The treatments consisted of control, 100% nitrogen (100% N), 100% nitrogen and phosphorus (100% NP), 50% nitrogen, phosphorus, and potassium (50% NPK), 100% nitrogen, phosphorus, and potassium (100% NPK), 150% nitrogen, phosphorus, and potassium (150% NPK), and 100% NPK+farmyard manure (100% NPK+FYM). Nutrients N, P, and K in 100% NPK treatment were applied at N: 120 kg ha—1, P: 26 kg ha—1, and K: 33 kg ha—1 each to maize and wheat crops and N: 20 kg ha—1, P: 17 kg ha—1, and K: 17 kg ha—1 to cowpea (fodder). In all the fertilizer and manure treatments removal of K in the crop exceeded K additions and the total soil K balance was negative. The neutral 1 N ammonium acetate‐extractable K in the surface soil (0—15 cm) ranged from 0.19 to 0.39 cmol kg—1 in various treatments after 27 crop cycles. The highest and lowest values were obtained in 100% NPK+FYM and 100% NP treatments, respectively. Non‐exchangeable K was also depleted more in the treatments without K fertilization (control, 100% N, and 100% NP). Parabolic diffusion equation could describe the reaction rates in CaCl2 solutions. Release rate constants (b) of non‐exchangeable K for different depth of soil profile showed the variations among the treatments indicating that long‐term cropping with different rates of fertilizers and manures influenced the rate of K release from non‐exchangeable fraction of soil. The b values were lowest in 100% NP and highest in 100% NPK+FYM treatment in the surface soil. In the sub‐surface soil layers (15—30 and 30—45 cm) also the higher release rates were obtained in the treatments supplied with K than without K fertilization indicating that the sub‐soils were also stressed for K in these treatments.  相似文献   

20.
Alarming climate change, rainfed upland farming, and low resource-use efficiency of conventional fertilizer management practices are major production constraints detrimental to rice productivity in the northwestern (NW) Himalayas. Recent agronomic intervention of direct-seeded rice (DSR) coupled with suitable rice germplasm well suited to rainfed upland ecosystems in combination with appropriate integrated nutrient-management (INM) technology can enhance the rice productivity in the region. Thus, a field experiment with seven treatments replicated three times in a randomized block design was conducted on INM technology in rainfed upland rice cv. HPR-1156 (Sukaradhan-1) to harness the potential of DSR technology in order to boost rice productivity in the NW Himalayas. Results on INM in direct-seeded upland rice revealed that nitrogen, phosphorus, and potassium (NPK) at 90:45:45 kg ha?1 + farm yard manure (FYM) at 5 t ha?1 (oven dry-weight basis) significantly resulted in the greatest magnitude of growth and development (plant height, tillers m?2) and yield-contributing characters (panicles m?2, panicle length, grains panicle?1 and 1000-grain weight), resulting in significantly greatest grain, straw, and biological yield followed by sole use of NPK at 90:45:45 kg ha?1 and NPK at 60:30:30 kg ha?1 + FYM at 5 t ha?1, respectively, in rainfed upland rice. Application of NPK at 90:45:45 kg ha?1 + FYM at 5 t ha?1 again resulted in significant improvement in soil organic carbon and available NPK status over other treatments and initial soil fertility status in an acidic Alfisol. Overall, it is inferred that INM technology with judicious use of NPK at 90:45:45 kg ha?1 + FYM at 5 t ha?1 in rainfed upland rice under DSR technology can enhance the rice productivity and resource-use efficiency in NW Himalayas.  相似文献   

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