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1.
An experiment was conducted at ICAR Research Complex for Eastern Region, Research Farm, Sabajpura, Patna (longitude 85°13′N and 1atitude 25°37′E), Bihar, India for four consecutive years 2004–05 to 2007–08 to develop a diversified cropping system for an irrigated ecosystem in Bihar by introducing pulse/oilseed/vegetables as a second or third crop in 10 rice-based cropping systems. Four crop cycles have been completed for all the cropping systems. During all years of the experiment there were significant variations among the cropping systems. Maximum paddy yield equivalent was recorded in rice–tomato–bottle gourd (40.44 t ha ?1) followed by rice–potato–onion (28.47 t ha ?1), rice–coriander–lady's fingers (26.79 t ha ?1), rice–carrot–cowpea (24.59 t ha ?1) and rice–mustard–tomato (24.44 t ha ?1). A higher value for the diversification index (DI) represents a higher level of crop diversification. It is evident from the results, that DI varies from 0.299 on a medium-sized farm to 0.903 on a small farm, with an average DI value of 0.643 among all farm categories. A survey revealed that the average DI value for small-scale farmers was highest (0.741) compared with the medium- (0.591) and large-scale (0.626) categories, and the differences were negligible. This seems reinforce the view that the smaller the farm, the higher the level of crop diversification. 相似文献
2.
Five wheat cultivars differing in tillering capacity and stature, Sahar-2006 (SH-06) (tall and low tillering), Faisalabad-2008 (FSD-08) (tall and low tillering), Lassani-2008 (LS-08) (medium stature and low tillering), Abdulstar-2002 (AS-02) (medium stature and high tillering) and Triple dwarf-1 (TD-1) (dwarf and low tillering), were planted in 10-, 20- and 30-cm spaced rows in a two-year study with same plant density. Higher grain yield in 20-cm spaced rows during both years and 30-cm spaced rows during the first year of the study in tall and low tillering wheat cultivars was attributed to more productive tillers, grains per spike and 1000-grain weight. However, the higher number of productive tillers resulted in better grain yield of the dwarf and low tillering cultivar under narrow row spacing. Higher leaf area index and crop growth rate were observed in 20- and 30-cm spaced rows 90 days after sowing, thereafter a drastic decrease was observed in 30-cm spaced rows. In conclusion, for harvesting maximum wheat productivity, tall and low tillering cultivars should be planted in 20-cm spaced rows. Medium stature and low tillering cultivars may be planted in 20 or 30-cm spaced rows, whereas low tillering dwarf cultivars should be planted in 10-cm spaced rows. 相似文献
3.
With increasing food demand worldwide, agriculture in semiarid and arid regions becomes increasingly important, though knowledge about organic matter (OM) conserving management systems is scarce. This study aimed at examining organic C (OC) and nitrogen (N) concentrations in various soil OM pools affected by 26-years application of chemical fertilizer and farmyard manure at an arid site of Gansu Province, China. Macro OM (>0.05 mm) was extracted by wet sieving and then separated into light macro OM (<1.8 g cm −3) and heavy macro OM (>1.8 g cm −3) sub-fractions; bulk soil was differentiated into free particulate OM (FPOM, <1.6 g cm −3), occluded particulate OM (OPOM, 1.6-1.8 g cm −3) and mineral-associated OM (>1.8 g cm −3). OC and N concentrations of heavy macro OM and FPOM were slightly affected by long-term N fertilization alone and its combination with P and K, but their magnitudes of change had not significantly contributed to total soil OC and N concentrations. Farmyard manure increased light macro OC and N by 58 and 70%, heavy macro OC and N by 86 and 117%, free particulate OC and N by 29 and 55%, occluded particulate OC and N by 29 and 55%, and mineral-associated OC and N by 44 and 48%, respectively, compared to nil-manure. Mineral fertilization improved soil OM quality by decreasing C/N ratio in the light macro OM and FPOM fractions where farmyard manure was absent. Organic manure led to a decline of the C/N ratio in all physically-separated OM fractions possibly due to the increased input of processed organic materials. We found about two thirds of macro OM was actually located within 2-0.05 mm organo-mineral associations or/and aggregates. In conclusion, this study stresses the vital importance to apply organic manure to the wheat-corn production system characterized by straw removal and conventional tillage in the region. 相似文献
4.
Summary The use of N and P by mixed and by sole cropping (crop rotation) of maize and cowpeas were compared in a field experiment on an Alfisol at the Nyankpala Agricultural Experiment Station in the northern Guinea Savanna of Ghana, using two levels of N (0 and 80 kg N ha -1 year -1 as urea) and P application (0 and 60 kg P ha -1 year -1 as Volta phosphate rock). Maize grain yields were significantly reduced in the mixed cropping system. This yield difference became smaller with the application of N and P fertilizer. The N and P concentrations in maize ear leaves at silking indicated that a deficiency in N and P contributed to the maize yield depression in mixed cropping. Competition for soil and fertilizer N between maize and cowpeas was suggested by: (1) A similarity in total N uptake between the two cropping systems; (2) efficient use of soil nitrate by the cowpeas; and (3) low N 2 fixation by the cowpeas, calculated with the aid of an extended-difference method. In general, N 2 fixation was low, with the highest values in the sole cropping (53 kg ha -1) and a substantial reduction in the mixed cropping system. The application of N fertilizer further reduced N 2 fixation. This was substantiated by nodule counts. The lower N 2 fixation in the mixed cropping system was only partly explained by the lower density of cowpeas in this system. In addition, dry spells during the cropping season and shading by the maize component could have reduced the nodulation efficiency. No N transfer from the legume/rhizobium to the non-legume crop was observed. Impaired P nutrition in the mixed compared with the sole-cropped maize might have been due to less P mobility in the soil. This was indicated by lower soil moisture contents in the topsoil under mixed cropping, especially during the dry year of 1986. The results show that mixed cropping of maize and cowpeas did not lead to improved use of soil and fertilizer N and P or to an enhanced N 2 fixation. On the contrary, an annual rotation of maize and cowpeas was clearly superior. 相似文献
5.
Systematic exportation, burning of crop residues and decreases in fallow periods have led to a large-scale depletion of soil organic matter and degradation of soil fertility in the cotton ( Gossypium hirsutum L.) cropping systems of Cameroon. The present study tested whether soil management systems based on a no-till with mulch approach intercropped with cereals, which has been shown to restore cotton production, could boost the biological activity of soil macrofauna. The impacts of no tillage with grass mulch ( Brachiaria ruziziensis Germain and Eward) (NTG) and no tillage with legume mulch ( Crotalaria retusa L. or Mucuna pruriens Bak.) (NTL) on the abundance, diversity and functional role of soil invertebrates were evaluated during the third year of implementation in northern Cameroon (Windé and Zouana), compared to conventional tillage (CT) and no tillage (NT) without mulch. Macrofauna were sampled from two 30 cm × 30 cm soil cubes (including litter) at the seeding stage of cotton, and 30 days later. The collected organisms were grouped into detritivores, herbivores and predators. Examination of the soil macrofauna patterns revealed that the abundance and diversity of soil arthropods were significantly higher in NTG and NTL than in CT plots (+103 and +79%, respectively), while that of NT plots was in-between the no tillage groups and CT (+37%). Regarding major ecological functions, herbivores and predators were significantly more abundant in NTG and NTL plots than in CT plots at Windé (+168 and +180%, respectively), while detritivores, predators and herbivores were significantly more abundant in the NTG plots than in CT plots at Zouana (+92, +517 and +116%, respectively). Formicidae (53.6%), Termitidae (24.7%) and Lumbricidae (9.4%) were the most abundant detritivores while Julidae (46.1%), Coleoptera larvae (22.1%) and Pyrrhocoridae or Reduviidae (11.8%) were the dominant herbivores. The major constituents of the predatory group were Araneae (33.8%), Carabidae (24.6%), Staphylinidae (15.7%) and Scolopendridae (10.3%). Direct seeding mulch-based systems, NTG and NTL, favoured the establishment of diverse macrofaunal communities in the studied cotton cropping system. 相似文献
6.
Continuous mono-cropping of rice-wheat (RW) system with conventional tillage (CT) based management practices have led to decline in soil health, groundwater table and farmers profit in north-west India. A medium-term (4 years) farmer’s participatory strategic research trial of basmati RW system was conducted to evaluate the effects of conservation agriculture (CA) based management practices on crop yields, water productivity, profitability and soil quality. Six treatments were compared varied in the cropping system, tillage, crop establishment and residue management. CA-based management under zero-till direct seeded rice-wheat-mungbean recorded 36% higher system yield than conventional till rice-wheat system (14.91 Mg ha ?1). CA-based rice-wheat system and rice-wheat-mungbean system saved ~35% irrigation water compared to conventional RW system (2168 mm ha ?1). Total water productivity (WP I+R) was improved by 67% with CA-based rice-wheat-mungbean system (0.90 kg grain m ?3) over the conventional system. On system basis, 42% higher net return was recorded with CA-based rice-wheat-mungbean system compared to conventional system (USD 2570 ha ?1). Mungbean integration in basmati RW system contributed 29% share in system net returns across the treatments. Soil chemical and biological properties were improved by ~40% and 150%, respectively, with CA-based management system. 相似文献
7.
ABSTRACTModern agriculture over the years has resulted in depletion of boron (B) from soil which has been emerged as a serious obstacle for sustainable agriculture. We studied the availability of B in soil and cauliflower ( Brassica oleracea var. botrytis L.) productivity under different levels of B fertilization. A field experiment was conducted during 2013–2014 and 2014–2015, at experimental farm of Himachal Pradesh Agricultural University, Palampur on silt-clay loam soil (acid Alfisol) under mid hill wet temperate condition. Different levels of B for the study included 0, 0.75, 1.5, 2.5, 5, 10, 20 and 30 kg B ha ?1 along with recommended dose (RD) of NPK and farmyard manure (FYM, 20 t ha ?1). The application of B influenced biological yield significantly up to 5 kg ha ?1. Highest curd yield in 2013–2014 (11.03 t ha ?1) and 2014–2015 (12.93 t ha ?1) was recorded in 1.5 and 0.75 kg ha ?1 B along with NPK + FYM, respectively. At higher rates of boron i.e. 10, 20 and 30 kg ha ?1, due to toxic effects, a reduction in curd yield was recorded in both years. Maximum mean uptake of N, P and K by leaves and curd was recorded with the application of boron at 1.5 kg ha ?1, whereas mean B uptake was highest when boron was applied at 2.5 kg ha ?1. The highest mean value (1.79 mg kg ?1) of soil available boron was recorded with 30 kg B ha ?1. Application of boron at 2.4 kg ha ?1 was worked out as optimum dose for cauliflower. 相似文献
8.
A two-year field experiment was conducted in Niger to explore the effects of integrated use of millet glume-derived compost (MGD-Compost) and NP fertilizer on soil microbial biomass carbon (C mic), nitrogen (N mic) and millet yields. Three compost rates (3000 kg ha ?1, 1500 kg ha ?1 and 0 kg ha ?1) and three NP fertilizer rates (100%, 50% and 0% of recommended NP fertilizer) were arranged in a factorial experiment organized in a randomized complete block design with three replications. Combined application of compost and NP fertilizer induced a synergistic effect on C mic and N mic. Compost application increased millet grain yield from 59% to 91% compared to control. Combined application of compost and NP fertilizer increased millet grain yields from 57% to 70% in 2013 and from 36% to 82% in 2014 compared to sole application of mineral fertilizer. Agronomic efficiency (AE) of nitrogen values increased by 3.7 and 2.3 times than those of sole NP fertilizer application in 2013 and 2014, respectively. Phosphorus AE was 1.6 times higher than that of the sole application of NP fertilizer. These findings indicate that integrated application of MGD-Compost and NP fertilizer enhances soil microbial biomass content and increases millet grain yield in a low-input cropping system. 相似文献
9.
Evaluating the effects of management practices on soil physical and chemical properties would be valuable to explain field-level variability in crop production. A 23-year-old experiment on a Muscatune soil (fine-silty, mixed, superactive, mesic, Aquic Argiudolls) in Illinois with five N rates [0 (N 0), 70 (N 1), 140 (N 2), 210 (N 3) and 280 (N 4) kg N ha −1] and two cropping systems [continuous corn ( Zea mays L.) (CC), and corn–soybean ( Glycine max (L.) Merr.) rotation (CS)] was evaluated. Specific objectives were to: (i) evaluate the effects of long-term N fertilization and cropping systems on field level changes in soil physical and chemical properties and crop yield, (ii) identify the most responsive soil physical and chemical properties to N fertilizer and crop management, and (iii) investigate the relationship between the selected soil properties and crop yield. Soil was collected in May 2004 to 30 cm depth and 20 soil physical and chemical properties were measured. The univariate analysis indicated that 14 soil properties were significantly influenced by at least one treatment effect (crops, N or crops × N). Due to multicollinearity among soil properties, principal component analysis (PCA) was used to group correlated properties, resulting in five soil properties such as soil organic carbon stock (OC stock), mean weight diameter (MWD), soil C:N ratio, exchangeable potassium (K +) and gravimetric moisture content ( ω). Finally, the multiple regression analysis performed between PCA derived soil properties and corn and soybean yields retained all the representative soil properties from PCA except ω as yield predictors for corn ( P < 0.001, R2 = 0.39) from CC system, whereas none of the soil properties were significantly related to corn and soybean yields from CS system. The soil properties most influenced by long-term N fertilization of continuous corn were successfully identified with PCA and multiple regression. The insignificant relationship between corn and soybean yields from CS system and PCA derived soil properties might be due to the lack of response of soybean to N fertilization. This study shows the integrated use of multivariate and regression analyses in identifying yield determining soil properties by eliminating the multicollinearity among soil properties. 相似文献
10.
Journal of Soils and Sediments - Fertilizer management is important for minimizing nutrient losses from intensive agroecosystems. An increasing amount of organic fertilizer has been applied to... 相似文献
11.
The effect of soil incorporations of lantana ( Lantana spp.) biomass, an obnoxious weed, on physical environment of a silty clay loam soil (Typic Hapludalf) under rice ( Oryza sativa L.)–wheat ( Triticum aestivum L.) cropping was studied in a long-term field experiment conducted in a wet temperate region of north India. Fresh lantana biomass was incorporated into the plough layer at 10, 20 and 30 Mg ha −1 annually, 7–10 days before puddling. Plant-available water capacity (PAWC), non-limiting water range (NLWR) and NLWR:PAWC ratio were determined to characterize soil physical environment during wheat crop in the tenth cropping cycle. Ten annual applications of lantana at 10, 20 and 30 Mg ha−1, increased organic carbon (OC) content over control by 12.6, 17.6 and 27.9% in 0–15 cm soil layer, and 17.1, 26.3 and 39.5% in 15–30 cm soil layer, respectively. The OC content in 0–15 and 15–30 cm soil layer of control plots was 11.1 and 7.6 g kg−1 soil. Bulk density decreased by 3–14% in 7.5–10.5 cm layer and 1–6% in 15–18 cm layer. Volumetric moisture contents at 10% air-filled porosity were 38.4, 40.0, 54.5 and 55.7% at 7.5–10.5 cm depth, and 31.4, 32.2, 33.9 and 34.6% at 15–18 cm depth corresponding to 0, 10, 20 and 30 Mg ha−1 lantana treatment, respectively. At 15–18 cm soil depth, volumetric moisture contents at 2 MPa soil penetration resistance were 26.9, 24.8, 23.0 and 19.6% in zero, 10, 20 and 30 Mg ha−1 lantana-treated plots, respectively. Lower soil water contents associated with 10% air-filled porosity and greater soil water contents associated with a limiting penetration resistance of 2 MPa resulted in a lower NLWR (4.3%) for control as compared to lantana-treated soil (7.4–15.1%). The PAWC showed slight increase from 12.9 to 13.4–14.9% due to lantana additions. The NLWR:PAWC ratio was also lower in control (0.33) as compared to lantana-treated soil (0.55–1.01). The NLWR was significantly and positively correlated with wheat grain yield (r=0.858**). 相似文献
12.
Summary The N uptake of maize was assessed on an Alfisol in a sole crop and in an alley cropping system in southwestern Nigeria. Although the application of prunings increased the maize N content in both sole and alley-cropped maize, the N contributed to the maize by the prunings was low, ranging between 4.4 and 23.8 kg ha –1. This was equivalent to 3.2% and 9.407% of the N released during decomposition of the prunings. Application of the prunings increased the grain yields of the sole maize by 38% and the maize yield in the alley-cropped plots by 104%, compared with yields in the corresponding plots where prunings were not applied. The results indicate that part of the N from the prunings was retained in the soil organic-N pool. Maize N, dry weights and grain yields were lowest in the alley-cropped plots where prunings were removed, probably because of competition between the maize and the hedgerow trees. 相似文献
13.
Seasonal changes in carbon availability and microbial biomass were studied in soil under an irrigated wheat-maize cropping
system receiving different fertilizter treatments over the past 10 years. Treatments included N-100 and N-200 (urea at 100
and 200kgNha –1 year –1, respectively), FYM-16 and FYM-32 (farmyard manure at 16 and 32tha –1 year –1, respectively) and a control (unfertilized). Aerobically mineralizable carbon (AMC; C mineralized after 10 days aerobic incubation
at 30°C) increased (13–16%) under wheat at both rates of urea whereas under maize it increased (22%) only with the lower rate
of urea. Farmyard manure also increased the content of soil AMC under both crops, the effect being two- to threefold higher
under wheat than under maize. Urea application caused an 32–78% increase in the specific respiratory activity (SRA) under
wheat but caused an 11–50% decrease during the maize season. Farmyard manure also resulted in a higher SRA under both crops
but only at the higher application rate. Under wheat, microbial biomass C (MBC) decreased in urea-treated plots but showed
a slight increase at the higher rate of FYM. During the maize season, MBC was higher under both urea (42–46%) and FYM (36–47%)
treatments as compared to the control. Microbial biomass turnover rate was highest for FYM-32 (2.08), followed by FYM-16 and
urea treatments (1.35–1.49); control plots showed a turnover rate of 0.82. The higher AMC and SRA during the active growth
period of wheat than that of maize indicated that root-derived C from wheat was higher in amount and more easily degradable.
Received: 16 April 1996 相似文献
14.
Three separate greenhouse experiments were conducted to determine the bi-directional N transfer in a peanut and rice intercropping system using the direct 15N foliar feeding technique at N application rates of 15, 75 and 150 kg ha –1. When peanut was used as the 15N donor plant, the atom % 15N in the rice shoot was consistently higher than in control rice, indicating that 15N transfer from peanut to the associated rice crop occurred. The percentage of N transfer (%NT) from peanut to the associated rice was 9.9%, 5.7% and 4.2% at the three N application rates, respectively. The N transferred from peanut to rice was 22.6, 15.5 and 8.2 mg N plant –1, accounting for 10.9%, 6.4% and 3.1% of the total N accumulated in rice plants at the three N application rates, respectively. When rice functioned as the 15N donor plant, the %NTs were 4.4%, 2.1% and 1.4% and represented about 5.2%, 3.4% and 2.4% of total N accumulated in peanut shoot at the three N application rates, respectively. The net directional N transfer was from peanut to rice and this was calculated by the difference in the bi-directional transfers and was mainly due to peanut root decomposition. Thus, the %NTs were 10.7%, 6.3%, 5.1% and 3.5% on 28 July (the day on which peanut shoots were cut), 8 August, 28 August and 8 September, respectively, and correspondingly, the N transferred from peanut to rice represented 6.0%, 5.8%, 5.1% and 3.2% of the total N accumulated in the rice plants. 相似文献
15.
The absorption of inorganic N by greenhouse vegetables is significantly influenced by seasonal variations in northern China. However, little research has been conducted on the effects of enhanced NH 4+–N on the growth, quality and fertilizer use efficiency of greenhouse tomato, which could provide the basis for N management in tomato plants under a continuous cropping system throughout the year. A field experiment was designed to study the responses of the photosynthetic characteristics, fruit qualities and water use efficiencies of tomatoes under a continuous cropping system under different N supplies. To summarize according to the equivalent N supply and the combined comprehensive weighing evaluation model, the quality, yield and efficiencies of tomato were closest to the ideal goals under the 30% and 20% NH 4+–N in the overwintering and early spring seasons, respectively. The quantitative index provides the basis for the comprehensive management of water and fertilizer at high yields. 相似文献
16.
Phosphorus (P) availability to plants is a major constraint in acid soils. A study was conducted to determine the effect of arbuscular mycorrhizal fungi (AMF) under varying inorganic P and irrigation regimes on P availability and P-use efficiency in garden pea ( Pisum sativum L.) in a Himalayan acid Alfisol. The experiment comprised of 14 treatments replicated thrice in a randomized block design. The results revealed that integrated use of AM fungi and inorganic P at either of the two irrigation regimes (IW/CPE 0.6 or IW/CPE 1.0) enhanced the green pea pod weight, green pod productivity and agronomic efficiency of applied P to the extent of 8.4%, 7.2% and 30.7%, respectively, over non-AMF counterparts as well as “generalized recommended NPK dose and irrigations (GRD).” AMF inoculation also led to enhanced nitrogen (N), P and potassium (K) acquisition (uptake) by 16.3%, 18.2% and 6% over non-AMF counterpart treatments. Further, AMF inoculation at varying P and irrigation regimes sharply enhanced the rooting depth (21.4%), root volume (23.5%), root dry weight (14.9%), root weight density (13.7%) as well as N concentration in root nodules (3.4%) over non-AMF counterparts and GRD practice. AMF also enhanced the mycorrhizal root colonization by 3.2 folds at flowering stage in AMF inoculated pea plants. AMF-imbedded treatments did not alter the available soil nutrient status ( macronutrients and micronutrients) significantly in comparison to non-AMF counterparts in pea, available P status, however, increased to the extent of 6.5% over initial status. Further, AMF imbedded plots showed a slight build-up in soil organic carbon with nominal decrease in soil bulk density. AMF inoculation in pea also led to fertilizer P economy by about 25% soil-test-based P dose. Overall, AMF holds great potential in enhancing nutrient acquisition especially P besides influencing root morphology in order to harness better crop yields vis-à-vis fertilizer P economy by about 25% soil-test-based P dose in Himalayan acid Alfisol. 相似文献
17.
In the area around Zaragoza, agrosystems are very fragile. Water is the main limiting factor for cultivation. Annual rainfall does not exceed 350mm, and the occurrence of convective storms with short and intense periods of very heavy rainfall greatly increases the danger of water erosion. Also, the mostly squeletic soils in this sparsely vegetated area are prone to erosion. In this semiarid environment, soil essentially constitutes a non-renewable resource, and therefore conservation of these agrosystems is an important issue and a serious environmental concern. Effective land management and soil conservation strategies require a variety of information and maps. In this paper, an expert land evaluation system (MicroLEIS) along with a geographic information system (IDRISI) are used to develop a computerized spatial database in order to suggest suitable land management strategies for environment conservation. 相似文献
18.
We compared the effects of saline stress (9:1 molar ratio of NaCl : Na 2SO 4, pH 6.44–6.65) and alkaline stress (9:1 molar ratio of NaHCO 3 : Na 2CO 3, pH 8.71–8.89) on the germination, growth, photosynthesis, ionic balance and activity of anti-oxidant enzymes of Lathyrus quinquenervius to elucidate the physiological adaptive mechanism of plants to alkaline stress (high pH). The results showed that, at a low stress intensity, the effects of saline stress and alkaline stress on L. quinquenervius were similar. Compared with saline stress, high alkaline stress intensity clearly inhibited germination, growth, photosynthesis and root system activity, and led to a sharp increase in Na + and an ion imbalance in the shoots, as well as enhanced H 2O 2 and malondialdehyde content, resulting in severe intracellular oxidative stress. The results indicated that the accumulation of organic acid was a central adaptive mechanism by which L. quinquenervius maintained intracellular ionic balance under alkaline stress. Lathyrus quinquenervius may enhance organic acid synthesis to remedy the shortage of negative charge resulting from the massive influx of Na + and decreased inorganic anions. In addition, saline stress and low alkaline stress slightly enhanced the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX), but did not affect catalase (CAT) activity. However, strong alkaline stress significantly enhanced the activities of SOD and APX, and reduced CAT activity. We propose that enhancing the activities of SOD and APX may be a vital mechanism by which L. quinquenervius resists oxidative stress caused by alkaline stress. 相似文献
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