scholarly journals Significant soil degradation is associated with intensive vegetable cropping in subtropical area: A case study in southwest China

2021 ◽  
Author(s):  
Ming Lu ◽  
David S. Powlson ◽  
Yi Liang ◽  
Zhi Yao ◽  
Dave R. Chadwick ◽  
...  
Keyword(s):  
Soil Degradation ◽  
Southwest China ◽  
Crop Residues ◽  
Management Strategies ◽  
Agricultural Practices ◽  
Nutrient Status ◽  
Fertilizer Application ◽  
Quality Parameters ◽  
Clear Trend ◽  
Soil C

Abstract. Within the context of sustainable development, soil degradation driven by land-use change is considered a serious global problem but conversion from growing cereals to vegetables is a change that has received little attention, especially in subtropical regions. Therefore, we compared the nutrient status and soil quality parameters (soil organic carbon [SOC], total nitrogen [TN], C / N ratio, pH, phosphorus [P], potassium [K], calcium [Ca], and magnesium [Mg]) between vegetable fields (VF) and land still used for paddy rice-oilseed rape rotation (PRF) that are typical of southwest China. In the VF, fertilizer application were often several times higher than the crop needs or recommended by the local extension service, thus, the crop use efficiency of N, P, K, Ca, Mg were only 26 %, 8 %, 56 %, 23 % and 28 %, respectively; SOC, C stock, TN, N stock decreased significantly caused by low organic inputs from crop residues and high tillage frequency, and soil C/N ratio decreased slightly; available P (AP) in topsoil increased by 1.92 mg kg−1 for every 100 kg ha−1 of surplus P, and the critical levels of AP and CaCl2-soluble P for P leaching were 104 and 0.80 mg P kg−1. Besides, there was a clear trend of soil acidification in the VF. However, increasing concentrations of soil Ca and Mg significantly alleviated topsoil acidification, with the effect increasing over time. Given our findings, we discuss the potential benefits of conservation agricultural practices, integrated soil-crop system management strategies and agricultural technology services for recovering the degraded soil and improving the vegetable productivity in the VF.

scholarly journals Phosphorus Budget for a Forested-Agricultural Watershed in Korea

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Arif Reza ◽  
Jaesung Eum ◽  
Sungmin Jung ◽  
Youngsoon Choi ◽  
Changwon Jang ◽  
...  
Keyword(s):  
Management Strategies ◽  
Sewage Treatment ◽  
Agricultural Practices ◽  
Fertilizer Application ◽  
Drainage Water ◽  
Agricultural Watershed ◽  
Application Rates ◽  
P Balance ◽  
Agriculture Fertilizer ◽  
Total P

Despite increased attention to the need for sustainable agriculture, fertilizer application rates above crop requirements remain common agricultural practices in South Korea, causing eutrophication of freshwater and coastal ecosystems. The aim of this study is to quantify phosphorus (P) inputs, outputs, and retention in a forested-agricultural watershed. The P budget showed that the combined use of chemical fertilizer and organic compost was the largest source of P (97.6% of the total) followed by atmospheric wet deposition (2.1% of the total P), whereas forest export (0.2% of the total) and sewage treatment plants (STPs) (0.1% of the total) were negligible. The P outputs were crop harvesting and hydrologic export to surface water. The P balance showed that P inputs are higher than the P outputs; approximately 87% of the total P input was retained in the soils within the watershed. However, P concentrations in drainage water were still high enough to cause eutrophication of downstream reservoirs. The results provide important details on the proportion of P export and retention in the watershed. This will help efforts to improve water quality and design better management strategies for agricultural nonpoint source pollution.

scholarly journals Perception of Farmers on Conservation Agriculture for Climate Change Adaptation in Namibia

2018 ◽  
Vol 8 (3) ◽  
pp. 33 ◽  
Author(s):  
M. Taapopi ◽  
J. M. Kamwi ◽  
N. Siyambango
Keyword(s):  
Crop Production ◽  
Crop Residues ◽  
Agricultural Practices ◽  
Conservation Agriculture ◽  
Fertilizer Application ◽  
Field Size ◽  
Face To Face ◽  
Entry Points ◽  
Negative Impacts ◽  
Smart Agriculture

Traditional cultivation methods in Namibia are characterised by cultivating the same type of crops persistently on the same piece of land, using a disc or mouldboard plough with minimal to no fertilizer application. This study assessed the knowledge level of farmers' on conservation agriculture and the household factors,which influence farmers to take up conservation agriculture in the Omusati Region of Namibia. Both socioeconomic and biophysical data were collected through household face-to-face interviews from 40 households located in seven constituencies of the Omusati Region. The results showed that technological know-how, limited agricultural inputs and implements for conservation agriculture hindered the uptake of conservation agriculture. In addition, lack of crop residues for mulching purposes and little understanding of the importance of crop rotation were identified as barriers to practice conservation agriculture. Logistic regression analysis showed that age, gender, marital status, education level, crop field size and farming period did not significantly influence the adoption of conservation agriculture. The study indicates that there is a need to encourage the use of climate smart agriculture technologies such as conservation agriculture, which minimizes the negative impacts of dry spells in order to maximize crop production and increase farmers'  understanding on the principles of conservation agriculture. Thus, strategies and policies to reduce poverty need to consider local contexts, social norms and values. In this regard, engagement of local farmers and demonstration of the short and long-term benefits of conservation agricultural practices offer promising entry points.

scholarly journals Application of Nematode Community Analyses-Based Models towards Identifying Sustainable Soil Health Management Outcomes: A Review of the Concepts

Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Haddish Melakeberhan ◽  
Gregory Bonito ◽  
Alexandra N. Kravchenko
Keyword(s):  
Nutrient Cycling ◽  
Health Management ◽  
Management Strategies ◽  
Soil Health ◽  
Agricultural Practices ◽  
Nematode Community ◽  
Parasitic Nematodes ◽  
Worst Case ◽  
Pests And Diseases ◽  
Water Holding

Soil health connotes the balance of biological, physicochemical, nutritional, structural, and water-holding components necessary to sustain plant productivity. Despite a substantial knowledge base, achieving sustainable soil health remains a goal because it is difficult to simultaneously: (i) improve soil structure, physicochemistry, water-holding capacity, and nutrient cycling; (ii) suppress pests and diseases while increasing beneficial organisms; and (iii) improve biological functioning leading to improved biomass/crop yield. The objectives of this review are (a) to identify agricultural practices (APs) driving soil health degradations and barriers to developing sustainable soil health, and (b) to describe how the nematode community analyses-based soil food web (SFW) and fertilizer use efficiency (FUE) data visualization models can be used towards developing sustainable soil health. The SFW model considers changes in beneficial nematode population dynamics relative to food and reproduction (enrichment index, EI; y-axis) and resistance to disturbance (structure index, SI; x-axis) in order to identify best-to-worst case scenarios for nutrient cycling and agroecosystem suitability of AP-driven outcomes. The FUE model visualizes associations between beneficial and plant-parasitic nematodes (x-axis) and ecosystem services (e.g., yield or nutrients, y-axis). The x-y relationship identifies best-to-worst case scenarios of the outcomes for sustainability. Both models can serve as platforms towards developing integrated and sustainable soil health management strategies on a location-specific or a one-size-fits-all basis. Future improvements for increased implementation of these models are discussed.

Growth and flowering of young cocoa plants is promoted by organic and nitrate-based fertiliser amendments

2020 ◽  
pp. 1-21
Author(s):  
Smilja Lambert ◽  
Hussin bin Purung ◽  
Syawaluddin ◽  
Peter McMahon
Keyword(s):  
Growth Rates ◽  
Block Design ◽  
Calcium Nitrate ◽  
Agricultural Practices ◽  
Aluminium Toxicity ◽  
Gliricidia Sepium ◽  
Available P ◽  
Average Growth ◽  
Organic Fertiliser ◽  
Soil C

Summary Cocoa (Theobroma cacao) farmers in Sulawesi, Indonesia typically use subsidised, ammonium-based rice fertilisers that in combination with poor agricultural practices have resulted in soil acidification, loss of organic matter, aluminium toxicity and lower soil fertility. As a result, these soils are only marginally appropriate for replanting cocoa to boost production. A field experiment was performed to test alternative soil amendments for successful replanting of cocoa on these deficient soils. In a trial with a randomised block design, 6-month old seedlings, top-grafted with the local MCC02 clone, were planted under light Gliricidia sepium shade and after 3 months treated quarterly with two options of mineral fertilisers: either a customised fertiliser, consisting of Nitrabor (a combination of calcium nitrate and boron), dolomite, rock phosphate and KCl or a NPK/urea mix used by farmers, each supplied with or without ‘micronutrient’ rock salt, organic fertiliser and beneficial microorganisms or their culture medium, a mixture of chitin and amino acids (a total of 20 treatments). Over a 4-year period, the marginal mean rates of stem diameter increment and flowering score were higher in customised fertiliser than NPK/urea treatments. The average growth rate was highest in the first year and was increased by supplying organic fertiliser. A significant correlation (r = 0.22, p < 0.05) occurred between growth and available P, but concentrations of available P were higher in the NPK/urea plots, which also had lower mean growth rates. Combined supply of organic fertiliser and microbes increased available P, as well as growth rates, in both the customised and NPK/urea treatments. In contrast, NPK/urea-treated plots without these amendments demonstrated very low growth rates. The customised formulation was more effective with or without added organic fertiliser or inoculated microbes. Micronutrient supply stimulated flowering. Growth rates in trees supplied with NPK/urea were also promoted by micronutrients. Leaf flush production occurred in regular cycles and was unaffected by the nutrient amendments. After 3 years, the customised and organic fertiliser application increased soil pH and exchangeable Ca and Mg concentrations, although they remained below recommended levels for cocoa production. These treatments had little impact on soil C content (about 1.3%) which was also deficient. Exchangeable Al and total Zn concentrations were higher in soils amended with NPK/urea. The results of the trial provide evidence that utilisation of organic fertiliser in combination with customised nitrate-based formulations improves cocoa establishment, growth and soil properties and should be recommended as a replacement for the NPK/urea fertilisers traditionally used by farmers.

Mulches and Nitrogen Application Improves Cotton Yield and Fiber Quality

2019 ◽  
Vol 1 (1) ◽  
pp. 09-13
Author(s):  
Hakoomat Ali ◽  
Asad Abbas ◽  
Shabir Hussain ◽  
Shoukat Ali Abid ◽  
Shazia Khaliq ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Crop Residues ◽  
Fiber Quality ◽  
Fertilizer Application ◽  
Cotton Yield ◽  
Nitrogen Application ◽  
Cotton Production ◽  
Nitrogen Levels ◽  
Important Cash Crop ◽  
Wheat Straw Mulch

Cotton is an important cash crop and source of foreign exchange. Nitrogen is a critical nutrient for plant growth throughout the life span of the crop. Wheat straw mulch not only source of nitrogen supply but also improves soil fertility and reduces soil erosion. The current study was performed to investigate the effects of mulches and nitrogen application on cotton productivity and fiber quality at the Central Cotton Research Institute (CCRI), Multan. Two crop residues i.e. wheat straw and non wheat straw were used in main plots while nitrogen levels viz. 0,50, 100 and 150 kg ha-1 were randomized in subplots. The highest seed cotton yield (22.99 t ha-1) was obtained by the combination of nitrogen fertilizer application highest level (150 kg N ha-1) along with the wheat straw (20.27 t ha-1). The fiber quality was also affected by the wheat straw along with nitrogen application 150 kg N ha-1 and gave maximum results. In conclusion, wheat straw along with 150 kg ha-1 of Nitrogen application gave maximum results on cotton production as compared to non straw with low nitrogen application.

scholarly journals Estimate of changes in agricultural terrestrial nitrogen pathways and ammonia emissions from 1850 to present in the Community Earth System Model

2016 ◽  
Vol 13 (11) ◽  
pp. 3397-3426 ◽  
Author(s):  
Stuart Riddick ◽  
Daniel Ward ◽  
Peter Hess ◽  
Natalie Mahowald ◽  
Raia Massad ◽  
...  
Keyword(s):  
Agricultural Practices ◽  
Animal Manure ◽  
Fertilizer Application ◽  
Global Scale ◽  
Reactive Nitrogen ◽  
Biogeochemical Model ◽  
Community Land Model ◽  
Synthetic Fertilizer ◽  
Rain Events ◽  
Percentage Basis

Abstract. Nitrogen applied to the surface of the land for agricultural purposes represents a significant source of reactive nitrogen (Nr) that can be emitted as a gaseous Nr species, be denitrified to atmospheric nitrogen (N2), run off during rain events or form plant-useable nitrogen in the soil. To investigate the magnitude, temporal variability and spatial heterogeneity of nitrogen pathways on a global scale from sources of animal manure and synthetic fertilizer, we developed a mechanistic parameterization of these pathways within a global terrestrial land model, the Community Land Model (CLM). In this first model version the parameterization emphasizes an explicit climate-dependent approach while using highly simplified representations of agricultural practices, including manure management and fertilizer application. The climate-dependent approach explicitly simulates the relationship between meteorological variables and biogeochemical processes to calculate the volatilization of ammonia (NH3), nitrification and runoff of Nr following manure or synthetic fertilizer application. For the year 2000, approximately 125 Tg N yr−1 is applied as manure and 62 Tg N yr−1 is applied as synthetic fertilizer. We estimate the resulting global NH3 emissions are 21 Tg N yr−1 from manure (17 % of manure production) and 12 Tg N yr−1 from fertilizer (19 % of fertilizer application); reactive nitrogen runoff during rain events is calculated as 11 Tg N yr−1 from manure and 5 Tg N yr−1 from fertilizer. The remaining nitrogen from manure (93 Tg N yr−1) and synthetic fertilizer (45 Tg N yr−1) is captured by the canopy or transferred to the soil nitrogen pools. The parameterization was implemented in the CLM from 1850 to 2000 using a transient simulation which predicted that, even though absolute values of all nitrogen pathways are increasing with increased manure and synthetic fertilizer application, partitioning of nitrogen to NH3 emissions from manure is increasing on a percentage basis, from 14 % of nitrogen applied in 1850 (3 Tg NH3 yr−1) to 17 % of nitrogen applied in 2000 (21 Tg NH3 yr−1). Under current manure and synthetic fertilizer application rates we find a global sensitivity of an additional 1 Tg NH3 (approximately 3 % of manure and fertilizer) emitted per year per °C of warming. While the model confirms earlier estimates of nitrogen fluxes made in a range of studies, its key purpose is to provide a theoretical framework that can be employed within a biogeochemical model, that can explicitly respond to climate and that can evolve and improve with further observation.

The distribution of organic carbon in major components of forests located in five life zones of Venezuela

1997 ◽  
Vol 13 (5) ◽  
pp. 697-708 ◽  
Author(s):  
M. Delaney ◽  
S. Brown ◽  
A. E. Lugo ◽  
A. Torres-Lezama ◽  
N. Bello Quintero
Keyword(s):  
Tropical Forests ◽  
Aboveground Biomass ◽  
Dead Wood ◽  
Clear Trend ◽  
Soil C ◽  
Forest Inventories ◽  
Biomass Components ◽  
Life Zone ◽  
Data Gap

ABSTRACTOne of the major uncertainties concerning the role of tropical forests in the global carbon cycle is the lack of adequate data on the carbon content of all their components. The goal of this study was to contribute to filling this data gap by estimating the quantity of carbon in the biomass, soil and necromass for 23 long-term permanent forest plots in five life zones of Venezuela to determine how C was partitioned among these components across a range of environments. Aboveground biomass C ranged from 70 to 179 Mg ha−1 and soil C from 125 to 257 Mg ha−1, and they represented the two largest C components in all plots. The C in fine litter (2.4 to 5.2 Mg ha−1), dead wood (2.4 to 21.2 Mg ha−1) and roots (23.6 to 38.0 Mg ha−1) accounted for less than 13% of the total C. The total amount of C among life zones ranged from 302 to 488 Mg ha−1, and showed no clear trend with life zone. In three of the five life zones, more C was found in the dead (soil, litter, dead wood) than in the live (biomass) components (dead to live ratios of 1.3 to 2.3); the lowland moist and moist transition to dry life zones had dead to live ratios of less than one. Results from this research suggest that for most life zones, an amount equivalent to between 20 and 58% of the aboveground biomass is located in necromass and roots. These percentages coupled with reliable estimates of aboveground biomass from forest inventories enable a more complete estimation of the C content of tropical forests to be made.

Changes in soil carbon under long-term maize in monoculture and legume-based rotation

2001 ◽  
Vol 81 (1) ◽  
pp. 21-31 ◽  
Author(s):  
E G Gregorich ◽  
C F Drury ◽  
J A Baldock
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Magnetic Resonance ◽  
Soil Carbon ◽  
Crop Residues ◽  
Cropping Systems ◽  
Natural Abundance ◽  
Organic C ◽  
Soil C

Legume-based cropping systems could help to increase crop productivity and soil organic matter levels, thereby enhancing soil quality, as well as having the additional benefit of sequestering atmospheric C. To evaluate the effects of 35 yr of maize monoculture and legume-based cropping on soil C levels and residue retention, we measured organic C and 13C natural abundance in soils under: fertilized and unfertilized maize (Zea mays L.), both in monoculture and legume-based [maize-oat (Avena sativa L.)-alfalfa (Medicago sativa L.)-alfalfa] rotations; fertilized and unfertilized systems of continuous grass (Poa pratensis L.); and under forest. Solid state 13C nuclear magnetic resonance (NMR) was used to chemically characterize the organic matter in plant residues and soils. Soils (70-cm depth) under maize cropping had about 30-40% less C, and those under continuous grass had about 16% less C, than those under adjacent forest. Qualitative differences in crop residues were important in these systems, because quantitative differences in net primary productivity and C inputs in the different agroecosystems did not account for observed differences in total soil C. Cropping sequence (i.e., rotation or monoculture) had a greater effect on soil C levels than application of fertilizer. The difference in soil C levels between rotation and monoculture maize systems was about 20 Mg C ha-1. The effects of fertilization on soil C were small (~6 Mg C ha-1), and differences were observed only in the monoculture system. The NMR results suggest that the chemical composition of organic matter was little affected by the nature of crop residues returned to the soil. The total quantity of maize-derived soil C was different in each system, because the quantity of maize residue returned to the soil was different; hence the maize-derived soil C ranged from 23 Mg ha-1 in the fertilized and 14 Mg ha-1 in the unfertilized monoculture soils (i.e., after 35 maize crops) to 6-7 Mg ha-1 in both the fertilized and unfertilized legume-based rotation soils (i.e., after eight maize crops). The proportion of maize residue C returned to the soil and retained as soil organic C (i.e., Mg maize-derived soil C/Mg maize residue) was about 14% for all maize cropping systems. The quantity of C3-C below the plow layer in legume-based rotation was 40% greater than that in monoculture and about the same as that under either continuous grass or forest. The soil organic matter below the plow layer in soil under the legume-based rotation appeared to be in a more biologically resistant form (i.e., higher aromatic C content) compared with that under monoculture. The retention of maize residue C as soil organic matter was four to five times greater below the plow layer than that within the plow layer. We conclude that residue quality plays a key role in increasing the retention of soil C in agroecosystems and that soils under legume-based rotation tend to be more “preservative” of residue C inputs, particularly from root inputs, than soils under monoculture. Key words: Soil carbon, 13C natural abundance, 13C nuclear magnetic resonance, maize cropping, legumes, root carbon

scholarly journals Potassium and Water-Deficient Conditions Influence the Growth, Yield and Quality of Ratoon Sugarcane (Saccharum officinarum L.) in a Semi-Arid Agroecosystem

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2257
Author(s):  
Rajan Bhatt ◽  
Jagdish Singh ◽  
Alison M. Laing ◽  
Ram Swaroop Meena ◽  
Walaa F. Alsanie ◽  
...  
Keyword(s):  
Insect Pests ◽  
Growth Yield ◽  
Fertilizer Application ◽  
Quality Parameters ◽  
Cane Yield ◽  
Yield And Quality ◽  
Fertilizer Application Rate ◽  
Significant Difference ◽  
K Fertilizer ◽  
Ratoon Sugarcane

Groundwater and soil potassium deficiencies are present in northern India. Sugarcane is a vital crop in the Indian Punjab; it is grown on approximately 91,000 hectares with an average yield of 80 tonnes ha−1 and a sugar recovery rate of 9.59%. The role of potassium (K) fertilizer under both sufficient and deficient irrigation in ratoon sugarcane crops is not well documented. We conducted a split-plot ratoon cane experiment during 2020–2021 at the Gurdaspur Regional Research Station of Punjab Agricultural University, India, on K-deficient soils. Main treatments were fully irrigated (I1) and water stressed (I0) conditions, with sub-treatments reflecting K fertilizer application rates of 0 (M1), 67 (M2), 133 (M3), and 200 (M4) kg K ha−1. The ratoon sugarcane performance was assessed in terms of growth, productivity, sugar quality and incidence of key insect pests. At harvest, trends in the growth and yield parameters in I1 were improved over the I0 treatment, with cane height (+12.2%), diameter (+3.3%), number of internodes (+5.4%), biomass yield (+7.6%) and cane yield (+5.9%) all higher, although little significant difference was observed between treatments. Ratoon cane yield under irrigation was 57.1 tonnes ha−1; in water-stressed conditions, it was 54.7 tonnes ha−1. In terms of sugarcane quality parameters, measured 12 months after harvesting the initial seed crop, values of Brix (+3.6%), pol (+3.9%), commercial cane sugar percentage (+4.0%) and extractable sugar percentage (+2.8%) were all higher in the irrigated treatments than the water-stressed plot. Irrigated treatments also had a significantly lower incidence of two key insect pests: top borer (Scirpophaga excerptalis) was reduced by 18.5% and stalk borer (Chilo auricilius) by 21.7%. The M3 and M4 treatments resulted in the highest cane yield and lowest incidence of insect pests compared to other K-fertilizer treatments. Economic return on K-fertilizer application increased with increasing fertilizer dosage. Under the potassium-deficient water-stressed conditions of the region of north India, a fertilizer application rate of 133 kg K ha−1 is recommended to improve ratoon sugarcane growth, yield, and quality parameters and economic returns for sugarcane farmers.

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