浅谈小麦施肥效应与土壤养分含量关系分析

小麦是中国种植较为广泛的农作物,研究小麦的施肥效应与土壤养分含量的关系,具有重要意义。通过研究不同的肥料和土壤养分的含量发现土壤氮素、速效钾含量是影响小麦生长的前两位肥料。肥料的回收利用率方面,随着施用氮肥的增加,氮肥的回收利用率率逐渐降低,而随着施用氮肥的增加,钾肥的回收利用率则先增高后下降。土壤全氮、有机肥方面,则随着氮肥的增加呈现增加的趋势。土壤的有效磷和速效钾含量则与氮肥和钾肥有密切关系,随着氮肥和钾肥的施肥量增加。

Effects of Nitrogen Fertilizer Application Mode on Sugarcane Yield and Soil Nutrient Change

[Objective] The aim was to improve use ratio of N fertilizer in sugarcane production and reduce N pol ution in agricultural production. [Method] With ROC22 as materials, N fertilizer quantities were set, including 38, 276 and 414 kg N/hm2, according to three fertilization approaches （approach 1： N fertilizer at 10% as base fertilizer, 30% N fertilizer applied to soil dressing, 60% N fertilizer applied to big ridging; approach 2： 30% N fertilizer as base fertilizer, 70% N fertilizer applied to soil dressing; approach 3： 100% N fertilizer as base fertilizer）. Some sugarcane in-dices, such as agronomic traits, yield and soil nutrients, were measured to research the relationship of N fertilizer with sugarcane growth and soil nutrients. [Result] Sug-arcane yield was increasing upon N fertilizer and reached the peak with N fertilizer at 276 kg N/hm2. In addition, early application of N fertilizer would promote sugar-cane jointing, growth and increase sugarcane yield. Nitrogen and available K con-tents were increasing upon N fertilizer, but excessive N fertilizer also caused soil acidification. N fertilizer applied early could help dissolve soil phosphate and improve phosphorus absorption and utilization. Applying N fertilizer completely as base fertil-izer was likely to cause N loss and low use efficiency. [Conclusion] The appropriate application mode for sugarcane is to apply N fertilizer twice at 138-276 kg N/hm^2.

Responses of Crop Yields and Soil Fertility to Long-term Nutrient Lacking

[Objective] Long-term （over 18 years） fertilization experiments were con- ducted to study the responses of crop yields and soil fertility to long-term nutrient lacking at Zhengzhou in China. [Method] The present study consisted of five treat- ments： 1 CK （no fertilizer or manure）, （2） NP （nitrogen and phosphorus fertilizer applied）, 31 NK （nitrogen and potassium fertilizer applied）, 4 PK （phosphorus and potassium fertilizer applied） and ：5 NPK （nitrogen, phosphorus and potassium fertil- izer applied）. [Result] Lacking of nitrogen or phosphorus led to a low yield; however, there was no significant difference in grain yields between the NP and NPK treat- ments which maintained a higher yield. Receiving no phosphorus, soil available phosphorus content declined to about 2.5 mg/kg. The concentration of soil ex- changeable potassium remained constant at a level of 60 mg/kg under the treat- ments without potassium fertilizer addition. Soil potassium spontaneous supply ca- pacity fluctuated around 100%.[Conclusion] In fluvo-aquic soil, nitrogen and phos- phorus were two key limiting factors to grain yields, biomass and yield component factors of wheat and maize, while potassium was not. However, potassium defi- ciency may occur in the future if there was still no potassium fertilizer applied.

Effect of Combined Application of Manure and Chemical Fertilizer on the Dynamic Changes of Purple Soil Nutrient and Soil Enzyme Activities

[Objective] The aim was to study the effects of combined of manure and fertilizer on the content of nutrients in purplish soil as well as release dynamics of enzyme activities.[Method] The effects of manure and fertilizer application on the content of AOM,NH＋4-N and NO-3-N in soil as well as release dynamics of enzyme activities were studied by means of simulation culturing.[Result] In the treatments of combined application of simulation culture experiment,the content of active organic matters,NH＋4-N,NO-3-N and soil enzyme activities changed dynamically,which showed a shape of inverted ＂S＂ with two or more peaks.Compared with the treatment of fertilization,their peaks were relatively flat and occurred relatively late,while the treatment of fertilization had only one but the highest peak.The content of active organic matter came to top around 10 d in the order of cow5fertilizer5pig5fertilizer5cow manurepig manurefertilizer Ⅰfertilizer Ⅱ;the activity of urease came to top around 10 d in all treatments and in the order of pig manurecow5fertilizer5cow manurefertilizer Ⅰfertilizer Ⅱpig5fertilizer5.The activity of saccharase was in the order of pig5fertilizer5pig manurecow5fertilizer5cow manureCKfertilizer Ⅱfertilizer Ⅰ.[Conclusion] The study could provide the theoretical basis for reasonable application of manure and fertilizer.

Effect of Continuous Application of Controlled Release Nitrogen Fertilizer in Various Types of Soil in Dong-Ting Lake Region under Double Rice Cropping System

[Objective] This study aimed to explore the effects of continuous application of controlled release nitrogen fertilizer under double rice cropping system. [Method] By modeling three types of paddy soils in Dong-Ting Lake area, four treatments as no fertilizer （CK）, urea, controlled release nitrogen fertilizer （CRNF） and 70% controlled release nitrogen fertilizer （70% CRNF） were designed in the micro-plot trials from 2005 to 2008. [Result] The rice yield in treatment CRNF at N 150 kg/hm2 was increased by 10.3%, 8.0% and 2.4% compared with treatment of urea, in alluvial sandy loamy paddy soil （ALS）, purple calcareous clayey paddy soil （PCS）, and reddish yellow loamy paddy soil （RYS）, respectively; and the yield in treatment of 70% CRNF was increased by 6.1%, 2.6% and -0.8%, respectively. The ranking order of nitrogen uptake amount by plant in early rice and late rice was CRNF 70% CRNF urea CK in all three types of soil. Nitrogen utilization efficiency of CRNF in above three types of soil was 60.7%, 59.6% and 56.3%, increased by 23.8%, 19.4% and 16.3% compared with that in treatment of urea, respectively. Nitrogen utilization efficiency of CRNF in early rice was increased year by year, and was higher than that of 70% CRNF during the whole experiment stage, while that in late rice was increased first and then decreased from the 3rd year. [Conclusion] Continuous application CRNF could alleviate the decreasing of soil nitrogen fertility and organic carbon especially in ALS, increase rice yield and nitrogen utilization efficiency in double-rice cropping system.

Study on Soil Nutrient Contents and Nutrient Characteristics of Ginger(Zingiber officinale Rosc.)

[Objective] This study was conducted to provide scientific basis for fertilization of ginger with high quality and high yield. [Method] The soil nutrient contents and plant nutrient characteristics of Zhugen ginger（Zingiber officinale Rosc.） were studied. [Result] The results showed that： the soil of ginger planting area in Chongqing（Yongchuan） Seedlings of science and technology city was acidic overall,the soil organic matter content was low and alkali-hydrolyzable N was at moderate level; and the contents of available P, Ca, Mg, Fe, Mn, Cu and Zn were extremely rich, while the available S was in lack. The contents of N and K were abundant and P was little in ginger plants, the content of K was more than N in ginger roots and stems, while the content of N was more than K in ginger leaves. [Conclusion]In practical production, it was necessary to fertilize rationally and control the ratio of N fertilizer to K fertilizer according to local conditions, thereby promoting ginger growth and realize high-yield ginger production.

Nutrient Uptake and Use Efficiency of Irrigated Rice in Response to Potassium Application

Potassium is one of the most important nutrients for rice production in many areas of Asia, especially in southeast China where potassium deficiency in soil is a widespread problem. Field experiments were conducted for four consecutive years in Jinhua City, Zhejiang Province, to determine utilization of nutrients (N, P and K) by inbred and hybrid rice and rice grain yields as affected by application of potassium fertilizer under irrigated conditions. Grain yield and nutrient harvest index showed a significant response to the NPK treatment as compared to the NP treatment. This suggested that potassium improved transfer of nitrogen and phosphorus from stems and leaves to panicles in rice plants. N and P use efficiencies of rice were not strongly responsive to potassium, but K use efficiency decreased significantly despite the fact that the amount of total K uptake increased. A significant difference between varieties was also observed with respect to nutrient uptake and use efficiency. Hybrid rice exhibited physiological advantage in N and P uptake and use efficiency over inbred rice. Analysis of annual dynamic change of exchangeable K and non-exchangeable K in the test soil indicated that non-exchangeable K was an important K source for rice. Potassium application caused an annual decrease in the concentration of available K in the soil tested, whereas an increase was observed in non-exchangeable K. It could be concluded that K fertilizer application at the rate of 100 kg ha-1 per season was not high enough to match K output, and efficient K management for rice must be based on the K input/output balance.

Analysis on Soil Nutrients and Formulated Fertilization Recommend of Rapeseed in Linxiang County,Yunnan Province

[Objective] The aim was to learn the soil nutrient status of the main rapeseed planting areas in Linxiang County,Yunnan Province,and propose full production potential of soil and fertilizer recommendations,thereby promoting local rapeseed production and income.[Method] The soil samples collected in field and tested in laboratory,with amount of fertilizer needed by rapeseed investigation were combined to calculate the formulated fertilization.[Result] Most of the soil organic matter and nutrient content of NPK were at the middle or higher level in the main rapeseed planting areas in Linxiang County.However,more than half of the soils were acidic or strongly acidic,and the soil p H maintained below 5.5.The shortage soil boron was more serious,the average content and nearly 60% of the sample of soil available boron were less than 0.5 mg/kg.[Conclusion] The formulated fertilization recommendations were identified as follows.To achieve the goal of 3 750 kg/hm^2240,150 and 75 kg/ha,if the application amount of manure was 15 000 kg/h,the total fertilizer N,P2O5,K2 O amount applied were separately 300,195 and 195 kg/hm^2.The chemical fertilizer N,P2O5,K2 O amount applied should be respectively 240,150 and 75 kg/hm^2,if the application amount of manure was 15 000 kg/hm^2.The nitrogen species of urea（containing N 46%）,causing weakest effect on soil acidification,was selected and applied about with 525 kg/hm^2.The alkaline calcium magnesium phosphate（P2O520%）,alternating superphosphate,was applied with about 750 kg/hm^2.Sulfuric acid potassium（K2O 50%） was applied with about 150 kg/hm^2.About 7.5kg/hm^2 borax was applied into soil as basal fertilizer,while spraying 7.5 kg/hm^2 fluid boron at the Bolting stag.

Sustainable Nutrient Management in Chinese Agriculture: Challenges and Perspective

China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.

Chemical and Microbiological Parameters of Paddy Soil Quality as Affected by Different Nutrient and Water Regimes

A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (SM), and chemical fertilizers with wheat straw (WS), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD), were investigated. With SM and WS total organic carbon and total nitrogen in the paddy soil were significantly higher (P < 0.05) than those with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WSC), and water-soluble organic C (WSOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARS). Meanwhile, as compared to CF, SM and WS significantly (P < 0.05) increased soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, SM and WS treatments significantly (P < 0.05) improved rice above-ground biomass and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.

Aerobic composting of paper mill sludge and the reuse of compost in agriculture

Paper mill sludge （PMS） is a kind of bio-solid waste. The technology of aerobic composting of PMS was investigated. The ratio of the material components was as follows, sludge：chicken dung：spill=6kg：2kg：4kg, which could attain 55% moisture content （MC） and 25 the ration of carbon to nitrogen （C/N）. The aeration rule of fan was controlled by single chip microcomputer （SCM）. During composting, the system temperature more than 55℃ lasted for 3 days, pH changed in the range of 6.5-8.5 and MC changed between 53% to 60%. PMS became mature on the 20th day. The germination index （GI） of compost attained 95% or so and coliform was 23/100 ml volatile solid （VS） and organic carbon （OC） were stable at the content of 60% and 30%, respectively. The result showed that this technology could make the sludge stable and innocuous. A pot experiment with latosolic red soil mixed with paper mill sludge compost （PMSC） was carried on. The result showed that PMSC could increase the crop biomass, the soil nutrients and the physical characteristics of the soil, such as OC, total nitrogen （TN）, total phosphorus （TP）. The total amount of heavy metals in the soil was measured to be lower than the Environmental standard for soil in China （GB15618-1995）. So PMSC was a good and safe soil amendment.

Effect of Slash Burning on Nutrient Removal and Soil Fertility in Chinese Fir and Evergreen Broadleaved Forests of Mid-Subtropical China

A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.

Fertilization for High Yields in Corn-Sweet Potato-Wheat Rotation: A Systematic Approach to Nutrient Limiting Factors of Soils in Chongqing, China

A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.

Human Activity and Soil Fertility-Nutrients Depletion of Arable Soils in China

The reserve of soil nutrients is limited. In case of irrational use of land, nutrients would be depleted sooner. Before the 1950s the low grain production in China was maintained only by expanding the cultivated area and by recycling of nutrients in agriculture. Calculation of nutrients balance showed that in the year of 1949 there were great deficits of N, P and K elements in agriculture of China. It revealed that there would have really been danger of soil nutrients exhaustion if such a situation had continued. Things have changed since the beginning of 1950s. The nutrients balance in agriculture has been getting better and better. In the year 1987 N and P balance got rid of their great deficits. But for K the deficit grew even larger. This resulted in a rapid expansion of soil area deficient in K in China since the mid 1970s. In spite of the fact that the P balance in the arable land of the whole country was positive, the field which did not receive P fertilizer had become deficient in P. So the area deficient in P also increased. It is stressed that great attention should be paid to the depletion of soil nutrients, especially K in the northern part of China where the soil is relatively rich in K. Of course, soil sulfur and microelements should be considered next.

Effects of Long-term Site-specific Fertilization on Soil Physical and Chemical Properties and Nutrients in Dry Farmland

In order to investigate the variation in soil physical and chemical properties and nutrients in the mountainous areas in southern Ningxia, and to provide a theoretical basis for fertilization management in local farmland, the soil p H, total salt content,crop root length, root weight, soil organic matter, available nitrogen, total nitrogen, total phosphorous and total potassium in different fertilization treatments were measured from 2010 to 2016. Multiple comparisons of the data were performed using Duncan's new multiple range test. The results indicated that in the 0-20 cm soil layer, soil p H value and total salt content changed in different patterns, and varied greatly from 2010 to 2016(P<0.05). The changes of both root length and root weight of millet over time fitted S-shaped curves. The root length and root weight in the four fertilization treatments(Treatment 2 to Treatment5) increased faster than those in the control(Treatment 1). The soil organic matter content in all the five treatments gradually increased from 2010 to 2016. The content of alkaline hydrolyzable nitrogen in soil rapidly increased in the first two to three years of the experiment, followed by a slow increase or decrease in 2013, and then raised rapidly again from 2014 to 2016.The soil total nitrogen content varied significantly from 2010 to 2016. The total phosphorus content in soil changed in a different pattern from that of total nitrogen content. The seven-year field trails revealed that soil p H, total salt content, root length, root weight and soil nutrient all changed with the increase of fertilizer level, and that long-term fertilization is of significance for maintaining soil fertility, improving soil quality and reducing soil salinization.

Impact Assessment of Oil Spillage on Farmlands of Some Communities in Ilaje Area of Ondo State, Nigeria

This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were within the Ikorigho and Otumara communities that recently experienced oil spillage and they are about 300 m from each other. While the third farm was within the Igbokoda community which is geographically similar but has not experienced oil spillage, it was used as control. The farmland was delineated at each area by the grid technique and soil samples were collected at 0-20 cm depth of the ground. Some physiochemical properties that reflect soil nutrient content and fertility status （pH, electrical conductivity, moisture content, organic matter, nitrogen, phosphorous and cation exchange capacity （CEC）） were determined using standard methods and results from the three areas were compared. There was a significant decrease in the calcium （Ca）, magnesium （Mg）, potassium （K） and organic matter, as well as a significant increase in the electrical conductivity, moisture content and phosphorous content of the oil-spill affected farmlands at Ikorigho and Otumara when compared with the non-affected farmland at Igbokoda. The acidic nature of the farmlands could not be attributed entirely to the oil spill since the control farmland at Igbokoda was slightly acidic. The results show that oil spillage has adversely affected the nutrient level and fertility status of farmland at Ikorigho and Otumara communities, which needs urgent remediation.

Effect of Biofertilizer on Biomass Productivity, Nutrient Balance and Soil Fertility in Rainfed Organic Ginger Production System

Farmers of North-Eastern India grow ginger organically and obtain low yield. Biofertilizer may help in increasing yield and maintaining soil fertility. An investigation made with different biofertilizers showed that seed treatment with biofertilizer increased biomass by 18.3%, enhanced N, P and K removal and improved short-term soil fertility status by increasing N and P balance and reducing negative K balance over control plots. Use of high dose （5.0 kg haL） of Azotobacter （a3） and medium dose （3.75 kg hal） of both Azospirillum （b2） and Phosphotica （c2） increased rhizome biomass by 6.8%-12.5% and shoot biomass by 5.6%-14.3% over other levels. They enhanced N, P and K removal by both rhizome and shoot when compared with other levels. The above biofertilizer treatments improved organic carbon and available N and P status of the soil by increasing N and P balance. The result showed overall strong negative K balance; but biofertilizer treatments greatly reduced the negative K balance in soil as compared to the control plots. Seed treatment with high level of Azotobacter along with medium level of Phosphotica （a3c2） produced the highest biomass yield （7.4 t hal）, increased N and P balance and fertility status in spite of hizh N, P and K removal.

Studies on the Effects of Polyaspartate Protease Fertilizer Enhancer in the Absorptions of Soil Nutrition and the Enzymatic Activities of Crops

The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.

Avocado Nutritional Diagnosis （Persea americana Mill.） ＂Hass＂, Soil Fertility and Water Quality in Ocuituco, Morelos

Morelos is the fourth in area cultivated and production volume of avocado. Of the 13 municipalities where it is farmed, Ocuituco represents 43.51% and Tetela del Volain 27.53%. Despite being one of the main fruit species in Morelos, no information related to the fertility of the soil where it is grown, the quality of water available for irrigation and nutritional status of this important fruit for the state. The study was conducted in the municipality of Ocuituco which identified three agro-habitats taking into account climate, landform, soil type and altitude. In each agro-habitat were carried out soil sampling to determine the physical and chemical characteristics based on the Mexican Official Standard NOM-021-SEMARNAT-2000, the chemical quality of water for irrigation as described by Richards （1954） and crop nutrient status of avocado ＂Hass＂ according to the methodology described by Maldonado （2002）. The soils had different physical and chemical characteristics, as well as the nutritional status of avocado trees in the three agro-habitats. The trees had excessive concentration of CI, Cu and Zn. Indices of optimal percentage deviation expressed different nutritional requirements. The water used for irrigation was of low salinity and sodium content, so it can be used without restrictions.

Fertility Status in Natural Succession and Reclamation Areas, ModADA-Papua, Eastern Indonesia

Tailings are the residue of mined material after separation of metals such as copper, gold and silver elements. Separation of minerals involves crushing of the host material to fine particles and separation of the metals by flotation or other technique. The total amount of tailings produced by Freeport Indonesia from their Grasberg mine is about 230,000 tons/day. These tailings are deposited in a lowland area and are confined by two levees. There are two types of plant growth on inactive tailings according to land use （natural succession area or reclaimed agricultural area）. This study of soil fertility on the mine tailing was required to contribute to information on the management oftailings. Representative sampling locations were chosen based on particle size distribution with soil （0- 5 50 cm depth） being subjected to laboratory analysis. Total N soil is very low （〈 0.02%）, CEC （≤20 me/100 g） low to medium, and organic-C ranges from 0.1-2%. oH is 7-8 resulting in the low availability of some nutrients, but values of extractable Cu may be high （≥ 300 mg/kg）. Nutrient elements are more abundant in soils on fine textured tailings.