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1.
Extension educates growers about using best management practices (BMPs) for nutrient management. However, it is important to understand grower management trends to prepare the best possible educational programs for growers. Three mail-based grower surveys conducted in 1981, 1996, and 2011 were used to document changing nitrogen (N) and phosphorus (P) fertilizer use and soil pH trends in the >450-mm precipitation zone of northern Idaho and eastern Washington, USA. The information collected in this paper spans a 40-year period. Nitrogen application rates have slightly increased, while P application rates on cereal crops have remained constant over the past 40 years. Average soil pH values have declined significantly over this time period; however, only about half of the surveyed growers were aware of this. This study is valuable because it (1) contains important information provided by growers on fertilization trends for the past 40 years (1971 to 2011), (2) quantifies the awareness of growers about soil pH decline in the region, and (3) provides baseline information, which can be used both in educational programming and to compare with future nutrient management.  相似文献   

2.
Rainfed Inceptisol soils, despite their agricultural potential, pose serious problems, including soil erosion, low fertility, nutrient imbalance, and low soil organic matter, and ultimately lead to poor soil quality. To address these constraints, two long-term experiments were initiated to study conservation agricultural practices, comprising conventional and low tillage as well as conjunctive use of organic and inorganic sources of nutrients in Inceptisol soils of Agra center of the All-India Coordinated Research Project for Dryland Agriculture (AICRPDA). The first experiment included tillage and nutrient-management practices, whereas the second studied only conjunctive nutrient-management practices. Both used pearl millet (Pennisetum americanum (L.) Linn) as test crop. These experiments were adopted for soil quality assessment studies at 4 and 8 years after their completion, respectively, at the Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, India. Soil quality assessment was done by identifying the key indicators using principal component analysis (PCA), linear scoring technique (LST), soil quality indices (SQI), and relative soil quality indices (RSQI). Results revealed that most of the soil quality parameters were significantly influenced by the management treatments in both the experiments. In experiment 1, soil quality indices varied from 0.86 to 1.08 across the treatments. Tillage as well as the nutrient-management treatments played a significant role in influencing the SQI. Among the tillage practices, low tillage with one interculture + weedicide application resulted in a greater soil quality index (0.98) followed by conventional tillage + one interculture (0.94), which was at par with low tillage + one interculture (0.93). Among the nutrient-management treatments, application of 100% organic sources of nutrients gave the greatest SQI of 1.05, whereas the other two practices of 50% nitrogen (N) (organic) + 50% (inorganic source) (0.92) and 100% N (inorganic source) (0.88) were statistically at par with each other. The various parameters that emerged as key soil quality indicators along with their percentage contributions toward SQI were organic carbon (17%), exchangeable calcium (Ca) (10%), available zinc (Zn) (9%), available copper (Cu) (6%), dehydrogenase assay (6%), microbial biomass carbon (25%) and mean weight diameter of soil aggregates (27%). In experiment 2, SQI varied from 2.33 to 3.47, and 50% urea + 50% farmyard manure (FYM) showed the greatest SQI of 3.47, which was at par with 100% RDF + 25 kg zinc sulfate (ZnSO4) (3.20). Under this set of treatments, the key soil quality indicators and their contributions to SQI were organic carbon (19%), available N (20%), exchangeable Ca (3%), available Zn (4%) and Cu (17%), labile carbon (20%), and mean weight diameter of soil aggregates (17%). The quantitative relationship established in this study between mean pearl millet yields (Y) and RSQI irrespective of the management treatments for both the experiments together could be quite useful to predict the yield quantitatively with respect to a given change in soil quality for these rainfed Inceptisols. The methodology used in this study is not only useful to these Inceptisols but can also be used for varying soil types, climate, and associated conditions elsewhere in the world.  相似文献   

3.
Grape (Vitis vinifera L.) production is a rapidly growing industry in North Carolina; however, no local-research-based information is available to support nutrient-management decisions. Field studies were initiated to survey soil and plant nutrient status over a wide range in geography and management conditions in the dominant V. vinifera regions in North Carolina. While the survey data are still being analyzed, significant information was initially obtained to identify aluminum toxicity and phosphorus and potassium deficiency as potential limiting factors to vine health and productivity. Field studies were initiated to quantify soil test and plant nutrient responses to lime, phosphorus, and potassium rates. Responses to phosphorus and potassium application were observed at most sites predicted by soil tests. However, lime responses were not observed in either petiole or blade samples collected at full bloom or veraison. These studies will be continued until sufficient response data are collected to establish soil test and plant nutrient diagnostic criteria for efficient nutrient management of V. vinifera in North Carolina.  相似文献   

4.
Abstract

In the past several years many scientists, consultants and growers in northern Idaho and eastern Washington have noticed a decline in the pH of agricultural soils. The purpose of this study was to compile and generate data for the determination of the causes, rate and magnitude of the pH decline in the region. Soil pH records from the past 40 years were collected from the soil testing laboratories at the University of Idaho and Washington State University. An intensive field pH survey was conducted in northern Idaho from 1982–84 and virgin soil samples were acidified under laboratory conditions.

Soils in northern Idaho and eastern Washington have undergone a rapid decline in pH in the past 25 years. These soils, which were near neutral in pH in their virgin state, have been acidified to the point that over 65% of the agricultural soils in the region have soil pH values less than 6.0. By 1984 over 45% of the agricultural soils in northern Idaho had pHs less than 5.6. This pH decline is attributed to the long‐term use of high rates of N fertilizers, as over 1250 kg N/ha have been applied to typical soils in the region since the virgin prairie sod was first broken for agricultural production. Seventy‐five percent of all N has been applied since 1960. Consequently, most soil acidification has occurred in the last 25 years. Field simulation in the laboratory was used to confirm the extent of soil acidification attributable to N fertilizer.  相似文献   

5.
Asiatic cotton (Gossypium arboreum) is mostly grown in the rainfed regions of India. However, little is known about the effects of nutrient‐management practices on plant growth and fruiting pattern of Asiatic cotton. Therefore, plant growth and fruiting pattern under four nutrient‐management treatments, N, NPK, FYM (10 Mg ha–1), and INM (integrated nutrient management: a combination of NPK and FYM) were quantified during 2000–01 to 2002–03 (years 16 to 18 of a long‐term field experiment). Plants of the INM and FYM treatments were taller (68.4–149.5 cm) and had more main stem nodes per plant (30.5–44.5) as compared to N and NPK treatments. In treatment N, the shortest plants (50.9–83.6 cm) and the least number of fruiting structures were produced. Plants of the INM and FYM treatments accumulated more squares and bolls. Maximum boll production was 10–19 days earlier with the manure‐amended than the N and NPK treatments. Treatment N had the lowest seed cotton yield (639–790 kg ha–1), because of small boll size (1.48–1.73 g) and few open bolls. Seed cotton yield followed the trend: NPK (815–1278 kg ha–1) < INM (776–1551 kg ha–1) < FYM (902–1593 kg ha–1). Water stress and nutrient deficiencies (P and Zn in the N and Zn in the NPK treatments) as a consequence of nutrient depletion over the years may have decreased seed cotton yields in treatments that received mineral fertilizer alone in comparison with manure‐amended treatments. On a long‐term basis, FYM application should therefore form an integral part of nutrient recommendation.  相似文献   

6.
Suppressing soil-borne diseases with residue management and organic amendments   总被引：15，自引：0，他引：15  
Changes in agricultural practices with time have led to a decline in soil structure and with it, an increase in soil-borne plant diseases. Agricultural practices such as incorporating organic amendments and managing the type and quantity of crop residue, have a direct impact on plant health and crop productivity. Soil management practices involving tillage, rotation, and burning will impact the amount and quality of organic matter that is returned to the soil. These practices influence pathogen viability and distribution, nutrient availability, and the release of biologically active substances from both crop residues and soil microorganisms as illustrated by the model system of Cochliobolus sativus on the development of common root rot in cereals. The application of organic amendments, manures and composts that are rich in nitrogen, may reduce soil-borne diseases by releasing allelochemicals generated during product storage or by subsequent microbial decomposition. The modes of action for disease suppression are elucidated for a number of diseases including verticillium wilt and common scab of potato. Developing disease suppressive soils by introducing organic amendments and crop residue management takes time, but the benefits accumulate across successive years improving soil health and structure.  相似文献   

7.
Abstract

In the high Andes, the traditional rotation is two or three years cropping with potatoes and cereals after 5 to 10 years of fallow. In the Bolivian Altiplano, the balance of available soil nitrogen (N) was monitored during 2 years of cultivation after 3 years of fallow. Two varieties of potato were planted in the first year as the head of the rotation. Potatoes or barley were planted in the second year. Fertilization with sheep dung was only applied for potato cropping. The dynamics of decomposition and N‐release of the amendment and the plant residues were measured using litterbag incubation in the field. Using the N‐release rates provided by the litterbag experiment, we modeled the fate of the mineralizable N originating from the sheep dung and the potato residues decomposition of a 2‐year succession to assess if the N supply from fertilization covered the plant demand.  相似文献   

8.
The uniformity, low cost and ease of application associated with inorganic fertilizers have diminished the use of organic nutrient sources. Concern for food safety, the environment and the need to dispose of animal and municipal wastes have focused attention on organic sources of N such as animal-derived amendments, green manures, and crop rotations. Managing organic N sources to provide sufficient N for crop growth requires knowledge of C and N decomposition over several years, particularly where manure and compost are applied. We report a comparison of compost and chemical fertilizer, use of a corn-corn-soybean-wheat rotation compared to continuous corn and the use of cover crops. Nitrogen (150 d) and C incubations (317 d) were conducted to determine the effect of cropping system and nutrient management on: N mineralization potential (NMP), the mineralizable organic N pool (No), the mean residence time (MRT) of No, C mineralization (Cmin), and soil organic carbon (SOC) pool sizes and fluxes. Compost applications over 6 y increased the resistant pool of C by 30% and the slow pool of C by 10%. The compost treatment contained 14% greater soil organic C than the fertilizer management. Nitrogen was limiting on all compost treatments with the exception of first year corn following wheat fallow and clover cover crop. The clover cover crop and wheat-fallow increased inorganic N in both nutrient managements. We recommend that growers adjust their N fertilizer recommendation to reflect the quantity and timing of N mineralized from organic N sources and the N immobilization that can be associated with compost or other residue applications. Proper management of nutrients from compost, cover crops and rotations can maintain soil fertility and increase C sequestration.  相似文献   

9.
The relatively poor accessibility, high costs, long turnaround time for analysis, and lack of information about soil and plant testing in the Andean highland region (Altiplano) of Bolivia has hampered informed and timely nutrient management decisions for potato (Solanum tuberosum L.) crops. The objective of this study was to determine if the Cardy nitrate meter (Horiba Ltd., Kyoto, Japan), a low-cost, portable, and rapid field test method, could be used to improve nitrogen (N) fertility management among isolated rural indigenous communities at different elevations in this rugged semi-arid environment. Fully matured leaf petioles were sampled at blooming time from potato trials established in three communities during the 2006–2007 and 2007–2008 growing seasons. Those trials were composed of 12 fertility treatments (i.e., an unfertilized control and different combinations of sheep and cow manure, inorganic fertilizer, commercial household/urban compost, and a commercial microbial activator soil amendment) arranged in a randomized complete block design with four replications. In general, in both growing seasons and in all communities, nitrate measured in the sap of leaf petioles by the Cardy meter had relatively low but significant correlations with leaf petiole total N (ranging from r2 = 0.07 to r2 = 0.60 across seasons and communities) and with total fresh tuber yield (ranging from r2 = 0.11 to r2 = 0.50 across seasons and communities). However, some problems were encountered with being able to consistently calibrate the meter with supplied standards prior to each use of the meter. These results indicate that the Cardy ion meter might be an effective tool for potato growers or agricultural professionals working in the Altiplano of Bolivia if further research can be conducted to determine if the meter is consistent for diverse sites in the Altiplano and is practical for the cultural, economic, and environmental conditions of the region.  相似文献   

10.
Foliar nutrient analysis is a useful diagnostic tool to complement soil testing as a best‐management practice with sugarcane (Saccharum spp.). This study was conducted to determine sugarcane production limits at leaf nutrient concentrations less than optimum. Eight Florida sugarcane growers participated in a survey of leaf nutrient values in 2004, 2005, and 2006. A total of 412 leaf samples were collected from individual commercial sugarcane fields, from which there were 389 harvest data/leaf data combinations. Fields were selected to be representative of plant cane, first ratoon, and second ratoon crops; mineral and organic soils of the area; and major commercial sugarcane cultivars. Leaf silicon (Si), magnesium (Mg), and manganese (Mn) concentrations had the strongest correlations with tons sugarcane ha?1 on organic soils, and leaf nitrogen (N), Mg, and Si concentrations had the strongest correlations with tons sugarcane ha?1 on mineral soils. Boundary lines were used to define practical limits of tons sugarcane ha?1 for leaf nutrient concentrations less than optimum. A table was developed that provides approximate leaf concentrations of nine nutrients at which 10 and 25% losses in relative tons sugarcane ha?1 were estimated. Boundary‐line analysis indicated that sugarcane production was most limited nutritionally in survey fields by insufficient Mg, iron, N, and Si on mineral soils and by insufficient Si and Mn on organic soils.  相似文献   

11.
Increasing the tuber number per plant and promoting tuber formation are important goals for potato production. Thus, it is of significance to understand how environmental factors affect tuber formation, which relates to the development of agronomical practices. The objective of this research was to test whether changing the CO2 or N supply level could alter the C : N ratio in potatoes, and whether a change of the C : N ratio in potatoes closely correlates with tuber formation in potato plants. Potato plantlets were grown in greenhouse with varied CO2 or N levels. The C and N concentrations of plants were measured, and the tuber number and tuber weight were recorded after different growth times. The results show that the C : N ratios in the potato plants increased with increasing CO2 concentration and that potato plants treated with higher CO2 concentrations form tubers earlier. A decrease in the N supply also resulted in a higher C : N ratio and earlier tuber formation. Therefore the hypothesis proposed previously is supported by the present work. In addition, the results that C concentration in plants remained stable under different CO2 or N levels imply that the variation of C : N ratio in the potato plants is mainly due to a change of N concentrations which decreased as the environmental CO2 concentration increased, while increased as the N supply level increased.  相似文献   

12.
Citrus production in Florida is ranked first in the United States. Success of the citrus industry in the state relies heavily on sound water and nutrient management practices. Recently, citrus production has been declining due to the escalating prevalence of the citrus greening (Liberibacter asiaticus) and canker (Xanthomonas axonopodis) diseases. One option being explored is the manipulation of nutrient management scenarios to increase and enhance tree productivity. The paper presents a review of the management, analytical and application methods of three major nutrients Nitrogen (N), Phosphorus (P), and Potassium (K) on Florida's sandy soils with low organic matter (OM) and high leaching potential due to heavy annual rains (～1200 mm). The NPK management options for Florida citrus are compared with those of other citrus producing regions around the world. Also, the critical tissue and soil nutrient concentrations for optimal and high citrus production are discussed. The review paper should provide important nutrient management guidelines to citrus growers in Florida and other regions with similar climatic and soil conditions.  相似文献   

13.
Field experiments were conducted on cotton to evaluate the different cotton-based intercropping system along with balanced nutrient management practices on enhancing cotton productivity. Cropping systems have been considered as main plots and nutrient management practices have been considered as subplots. The results showed that cotton + onion system recorded the highest cotton equivalent yield (CEY) of 2052 and 1895 kg ha?1 which was on par with cotton intercropped with dhaincha, which recorded 2010 and 1894 kg of CEY ha?1 in both the seasons. Combined application of 100% recommended NPK with bioinoculants (S5) registered highest CEY in both the seasons. Cotton intercropped with dhaincha (M2) recorded highest uptake of N, P, and K. Among the nutrient management practices, application of 100% recommended NPK with bioinoculants (S5) showed highest uptake of N, P, and K. A similar trend was noticed in the post-harvest soil fertility too and it is significantly higher under cotton + dhaincha and application of 100% recommended NPK with bioinoculants treatment compared to 100% recommend NPK alone. It could be concluded from these results that crop productivity can be improved and soil fertility status can be sustained with integrated plant nutrient management practices.  相似文献   

14.
Soils in the hot, arid topical regions are low in organic matter and fertility and are structurally poor. Consequently, these soils suffer on account of poor physical, chemical, and biological soil quality traits, leading to miserably low crop yields. Long-term use of conjunctive nutrient management and conservation tillage practices may have a profound effect on improving the quality of these soils. Therefore, the objective of this study was to identify the key soil quality indicators, indices, and the best soil- and nutrient-management practices that can improve soil quality on long-term basis for enhanced productivity under a pearl millet–based system. The studies were conducted for the Hissar Centre of All-India Coordinated Research Project at the Central Research Institute for Dryland Agriculture, Hyderabad. Conjunctive nutrient-use treatments and conservation tillage significantly influenced the majority of the soil quality parameters in both the experiments. In experiment 1, the key soil quality indicators that significantly contributed to soil quality in a rainfed pearl millet–mung bean system were available nitrogen (N, 35%), available zinc (Zn; 35%), available copper (Cu; 10%), pH (10%), available potassium (K; 5%), and dehydrogenase assay (5%). The three best conjunctive nutrient-use treatments in terms of soil quality indices (SQI) were T3, 25 kg N (compost) (1.52) > T6, 15 kg N (compost) + 10 kg N (inorganic) + biofertilizer (1.49) > T5, 15 kg N (compost) + 10 kg N (green leaf manure) (1.47). In experiment 2, under a rainfed pearl millet system, the key indicators and their percentage contributions were electrical conductivity (15%), available N (19%), exchangeable magnesium (Mg; 18%), available manganese (Mn; 13%), dehydrogenase assay (19%), microbial biomass carbon (C; 5%), and bulk density (11%). The three best tillage + nutrient treatments identified from the viewpoint of soil quality were T1, conventional tillage (CT) + two intercultures (IC) + 100% N (organic source/compost) (1.74) > T3, CT + two IC + 100% N (inorganic source) (1.74) > T4, low tillage + two IC + 100% N (organic source/compost) (1.70). The findings of the present study as well as the state-of-the-art methodology adopted could be of much interest and use to the future researchers including students, land managers, state agricultural officers, growers/farmers, and all other associated stakeholders. The prediction function developed between long-term pearl millet crop yields (y) and soil quality indices (x) in this study could be of much use in predicting the crop yields with a given change in soil quality index under similar situations.  相似文献   

15.
The use of conservation tillage systems is now widespread for cereals in erosion-prone areas of Norway. However, few growers are willing to adopt such practices for other crops. An experiment was conducted in southern Norway (60°46′N, 10°49′E) from 1987 to 1993 to compare the effects of two different tillage treatments on potato (Solanum tuberosum L.) yield and quality. The conventional labour-intensive treatment, with autumn mouldboard ploughing, levelling and two passes with a spring-tine harrow in spring was compared with planting directly into untilled barley (Hordeum vulgare L.) stubble, with straw removed. The soil type in the experiment was a morainic, stony loam (Typic Cryoboroll, Orthic Melanic Brunisol). Prior to the start of the experiment direct-planted plots had not been ploughed for 9 years. During the trial years (1987–1993) a pattern of two different yield curves emerged as functions of the date of harvesting. The yield curve for direct planting was steeper, crossing that of conventional tillage on approximately 10 September, thus predicting higher tuber yield for direct planting when harvesting occurred after this date, but lower tuber yield than with conventional tillage in the case of early harvesting. The reason for this is thought to be cooler soil and delayed growth and maturation with direct planting. Furthermore, direct planted potatoes gave higher haulm yield, and also had higher contents of N, P and K in both haulm and tubers. No significant differences in tuber quality were found between the two treatments. A strong negative correlation was found between the yield increase caused by direct planting and mean air temperature in August. The trial indicated that direct planting of potatoes in cereal stubble is a viable alternative to conventional plough tillage on loam soil in Norway, provided that the growing season is adequately long.  相似文献   

16.
In a field study of irrigated chile (Capsicum annum L.) production in southeastern Arizona and southwestern New Mexico from 2008 through 2009, soil and tissue test samples were analyzed for a spectrum of plant nutrients at 16 different sites, including nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), iron (Fe), and boron (B). The objectives were to evaluate soil and tissue nutrient testing procedures and to establish basic soil and plant tissue-testing guidelines and recommendations with respect to yield potentials. Soil samples were collected before planting. Plant tissue samples from plots at all sites were collected at the following four stages of growth: first bloom (FB), early bloom (EB), peak bloom (PB), and physiological maturity (PM). Fertilizer and nutrient inputs were monitored, managed, and recorded within current extension guidelines for irrigated chiles. Results for soil and tissue analyses were compared to yield results. The results provide estimates for baselines, which can be tested through subsequent calibration experiments to establish recommendations for critical soil- and tissue-test values. Absolute minimum soil-test nutrient values were identified as 10 parts per million (ppm) P, 110 ppm K, 0.3 ppm Zn, 2.0 ppm Fe, and 0.25 ppm B. Absolute minimum FB leaf tissue test values were 0.2% P, 4.5% K, 10 ppm Zn, 80 ppm Fe, and 30 ppm B. Complete data sets for leaf and petiole tissue-test values for all stages of growth were collected. These soil-test and plant nutrient values will be evaluated in subsequent experiments to better define fertilizer nutrient inputs and to gain better nutrient-management efficiencies in irrigated chile production systems.  相似文献   

17.
The present long-term study was initiated to quantify the long-term effects of conjunctive nutrient management on soil quality, identify key indicators, and assess soil quality indices under a rainfed maize–wheat system in marginal Inceptisol soils in India. Results of the study revealed that soil organic carbon was significantly influenced by the conjunctive nutrient-management treatments. Among the nine treatments, the application of 100% recommended dose of nitrogen (RDN) (80 kg N ha?1), 15 kg N (compost) + 20 kg N ha?1 (inorganic), 25 kg N (compost), and 15 kg N (compost) + 10 kg N ha?1 (green leaf) resulted in greater organic carbon contents of 5.57, 5.32, 5.27, and 5.26 g kg?1, which were greater by 29.5%, 24%, 23%, and 22%, respectively, over the control. The greatest soil quality index (1.61) was observed with application of 25 kg nitrogen (N; compost) as well as with application of 15 kg N (compost) + 10 kg N ha?1 (green leaf). The order of percentage contribution of key indicators toward soil quality indices was available potassium (K) (34%) > available phosphorus (P) (32%) > available N (13%) > microbial biomass carbon (12%) > exchangeable calcium (Ca) (9%). The linear regression equation revealed the principal role of soil quality indicators in maize crop yield. The methodology and the results of the study could be of great relevance in improving and assessing soil quality not only for the study locations but also for other climatically and edaphically identical regions across the world.  相似文献   

18.
我国马铃薯产量和化肥利用率区域特征研究   总被引：5，自引：2，他引：3  
【目的】本研究汇总马铃薯(Solanum tuberosum L.)田间试验数据,分析中国马铃薯产区施用氮、磷和钾肥的马铃薯产量(可获得产量、产量反应和相对产量)及肥料利用率特征,以期为优化马铃薯养分管理奠定理论基础。【方法】本试验数据来源于:1)国际植物营养研究所(International Plant Nutrition Institute, IPNI)1992—2012年间在我国马铃薯主产区开展的117个田间试验;2)采用字段或字段组合(马铃薯,马铃薯+产量,马铃薯+利用率,等)在中国知网数据库(China National Knowledge Infrastructure, CNKI)检索的2000—2016年间407篇马铃薯田间试验中文文献。将我国马铃薯种植区分为东北(NE)、西北(NW)、华北(NC)、长江中下游(MLYR)、东南(SE)和西南(SW)产区。试验处理包括氮磷钾肥优化处理(OPT)、不施氮(OPT-N)处理、不施磷(OPT-P)处理和不施钾(OPT-K)处理,研究我国马铃薯不同种植区优化施肥下马铃薯可获得产量,氮、磷和钾肥产量反应,相对产量,农学效率,偏生产力和养分回收率特征。【结果】我国马铃薯施用氮、磷和钾产量反应平均分别为8.6、5.9和6.6 t/hm^2,氮素是马铃薯产量的首要限制因子,东北地区产量及施氮产量反应平均值显著高于其他地区(P <0.05)。马铃薯施氮、磷、钾相对产量平均值分别为71.0%、79.4%、77.2%,其中,华北地区施氮相对产量平均值最高,东南地区施磷相对产量平均值最高,西北地区施钾相对产量平均值最高。马铃薯氮、磷和钾肥用量平均分别为N 164.2 kg/hm^2、P_2O_5 100.3 kg/hm^2和K_2O 188.0 kg/hm2,东南地区氮和钾肥用量平均值显著高于其他地区(P <0.05),东北地区施氮量和施钾量较低,东北、西南和西北施磷量高于其他地区,长江中下游施磷量最低。马铃薯氮、磷和钾素农学效率平均值分别为52.2 kg/kg N、58.5 kg/kg P_2O_5和42.3 kg/kgK_2O,东北地区氮和钾素农学效率平均值显著高于其他地区(P <0.05)。马铃薯氮、磷和钾素偏生产力平均值分别为205.7 kg/kg N、339.0 kg/kg P_2O_5和209.2 kg/kg K_2O,东北地区氮和钾素偏生产力平均值分别显著(P <0.05)高于其他地区。马铃薯氮、磷和钾素养分回收率平均值分别为36.4%、18.5%和27.6%,东南地区磷素回收率平均值显著高于其它地区(P <0.05)。【结论】我国马铃薯不同产区产量、施肥量和肥料利用率差异较大,氮素是马铃薯产量的第一限制因子,华北地区氮素、东南地区磷素和西北地区钾素土壤基础养分供应能力相对较高,不同地区马铃薯需要因地制宜,制定有针对性的马铃薯优化施肥方案。  相似文献   

19.
The composting of organic waste materials using earthworms yields the value-added product vermicompost (VC). The use of VC as a growing substrate amendment for containerized horticultural crop production is a sustainable nutrient management approach which can benefit crop production by providing plant nutrients and improving crop growth. In order to provide nutrient management guidelines for users of VC amended container substrates, a study was conducted to quantify nutrients supplied to substrates solution and to develop nutrient release kinetic models to predict plant available nutrient based on total initial loading rates. Experimental treatments and results were expressed on a volume basis (4-L container) for easy interpretation and application by growers of crops in containers.  相似文献   

20.
The vine-growing region of Lumbarda, located in the southeastern part of the island of Korcula, Croatia, has deep sandy soils (paleodunes) associated with the Mediterranean climate and provides optimal conditions for cultivating the autochthonous vine variety Vitis vinifera L. cv. Grk. Unfortunately, recently growers have noted declining yield and quality of grapes resulting from inadequate vineyard management (particularly unsustainable management of soil organic matter) and the occurrence of viral diseases. To revitalize and maintain the vineyards in the Lumbarda region, a detailed study was carried out involving intensive soil survey, analysis of grapevine nutrient status, positive clonal selection, and establishment of new vineyards with virus-free plant material. Preliminary soil survey results provided insight into the extent of variability in major physical and chemical soil characteristics. Based on these results, eight markedly different vineyards were selected for detailed analysis of grapevine nutrients [boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), and zinc (Zn)] at key development stages to detect potential imbalances that may hamper vine growth and affect its production. Leaf blades and petioles were sampled at midflowering and midveraison stages during the 2007–8 growing season from each of the selected vineyards. The greatest variability in nutrient content between the study sites was recorded for Cu, and considerable variability was also determined for B, Mn, Mg, and P. Differences in fertilization practices are the most common reasons for this variability. The results point to B deficiency in some of the vineyards and suggest potentially toxic levels of Cu in others.  相似文献   

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