Organic N Fertilizers and Irrigation Influence Organic Broccoli Production in Two Regions of California

2007 ◽  
Vol 12 (4) ◽  
pp. 27-46 ◽  
Author(s):  
Sajeemas Pasakdee ◽  
Gary Bañuelos ◽  
Carol Shennan ◽  
Weixin Cheng
Keyword(s):  

1994 ◽  
Vol 38 (2) ◽  
pp. 131-139 ◽  
Author(s):  
S. Sen ◽  
P. M. Chalk
Keyword(s):  


2012 ◽  
Vol 610-613 ◽  
pp. 3027-3033
Author(s):  
Da Lan Feng ◽  
Yan Jin ◽  
Yu Hong Yang ◽  
Jian Guo Huang

An incubation experiment was carried out to study various available N pools and enzyme activities in the soil near fertilizers under controlled temperature and soil moisture. Fertilizers added into soil were chemical fertilizer supplied as urea, organic fertilizer as rapeseed straw, and mixture of urea and rapeseed straw in a ratio of 7:3, respectively. 30 days after incubation, NH+4-N, NO-3-N and 1 N NaOH- hydrolyzed N increased in the soil at < 2.5 cm from the fertilizers in two lateral directions, and progressively decreased as the distance to the fertilizers increased. The results indicated the intensive available N release from the fertilizers and easy movement of fertilizer N. Taking into account of dense roots in cultivated soil layers and easy migration of N fertilizers, broadcast application of N fertilizers could be efficient in the middle growing periods of crops. There was neither obvious influence of urea application on urease activity nor significant correlation between urease activity and NH4+-N in the soil. Therefore, it seems reasonable to suggest that urea hydrolysis catalyzed by urease might be fast, unlikely the rate-limiting step in the process of urea transformation into NH4+-N. Further study showed the high activities of saccharase and protease in the soil only at 0.25 cm from the organic fertilizers added either in pure rape straw or mixture with urea. Saccharase and protease on the interface between organic fertilizer and soil could thus accelerate N release of organic fertilizers as available forms through organic N decomposition, resulting in the high available N pools in the soil near organic fertilizers.



2010 ◽  
pp. 134-140
Author(s):  
Andrea Balla Kovács ◽  
Anita Szabó ◽  
Emese Bartáné Szabó

A field experiment was conducted to examine the effects of different nitrogen fertilizers in combination with bacterial fertilizer onnutrient uptake of horseradish and plant available nutrients of the soil. Three different N fertilizers, ammonium-nitrate, urea and calciumnitrate(116 kg ha-1 N) in combination with Microbion UNC bacterial fertilizer (2 kg ha-1) were applied as treatments in a randomizedcomplete block design in three replications. In this paper we presented the results of soil measurements. The soil of the experimental areawas chernozem with medium sufficiency level of N and P and poor level of K.Our main results:The amount of 0.01M CaCl2 soluble inorganic nitrogen fractions, NO3--N and NH4+-N and also the quantity of soluble organic-N werealmost the same in the soil. N fertilizers significantly increased all the soluble N fractions. The amount of NO3--N increased to the greatestextent and the increase of organic N was the slightest. We measured the largest CaCl2 soluble NO3- -N and total-N contents in the plotstreated with ammonium-nitrate, the largest NH4+-N in the plots treated with calcium-nitrate and the largest organic-N fraction in plotstreated with urea.Bacterial inoculation also increased both soluble inorganic nitrogen forms and also total-N content of soil compared to the control. Inthe case of combined (artificial and bacterial fertilizer) treatments we measured lower NO3--N, organic-N and total-N compared to thevalues of plots having only nitrogen fertilizer treatments. On the contrary in the plots with combined treatments the CaCl2 soluble NH4+-Ncontent of soil in more cases were higher than that of values with artificial fertilizer treatment.As a function of calcium-nitrate application increased AL-P2O5 and AL-K2O values were measured compared to control. MicrobionUNC supplement of calcium nitrate yielded also increase in AL-P2O5 and AL-K2O values, till then supplement of ammonium-nitrate fertilizeryielded a decrease in these values compared to the control.All nitrogen fertilizers resulted in a significant decrease in AL-Mg content of soil compared to the control. Nevertheless bacterialfertilizer increased AL-Mg values in any cases.



Author(s):  
Markus T Lasut ◽  
Adianse Tarigan

A study on water quality status of three riverine systems, S. Bailang (SB), S. Maasing (SM), and S. Tondano (ST), in coastal city of Manado, North Sulawesi Province, has been conducted to measure several water quality parameters, to analyse source and quality of wastewater discharge, and to assess the status of the rivers related to the water quality. Measurement of the parameters was conducted using three indicators, i.e. organic (BOD5) and in-organic (N-NO3 and P-PO4), and pathogenic microorganism (Escherichia coli [EC] and total coliform [TC]). The result showed that the level of water quality varied between the rivers. The average level of water quality (based on the observed parameters) in SB, respectively, was 0.317 mg/l, 0.093 mg/l, 2 mg/l, >2420 MPN, and  >2420 MPN; in SM, respectively, was 0.029 mg/l, 1.859 mg/l, 17.7 mg/l, >2420 MPN, and >2420 MPN; and in ST, respectively, was 0.299 mg/l, 0.252 mg/l, 3.5 mg/l, >2420 MPN, and >2420 MPN. The level of water quality between the rivers was not significantly different (p>0.05), except based on the parameter of N-NO3 which was significantly different (p<0.01). The status of the observed rivers varied based on the classes of their water utilities (according to the Government Regulation of Indonesia, No. 82, 2001); mostly was "unsuitable". Kajian tentang status kualitas air di 3 perairan sungai di kota pesisir Manado, S. Bailang (SB), S. Maasing (SM), dan S. Tondano (ST), Provinsi Sulawesi Utara, telah dilakukan yang bertujuan untuk mengukur beberapa parameter kualitas air, menganalisis sumber dan kualitas buangan limbah domestik, dan menilai status ketiga perairan sungai tersebut. Tiga indikator digunakan, yaitu: bahan organik (BOD5), bahan anorganik (N-NO3 dan P-PO4), dan mikroorganisme patogenik (Escherichia coli [EC] dan coliform total [TC]). Hasil kajian menunjukkan bahwa tingkat kualitas air perairan tersebut berbeda-beda. Konsentrasi rerata parameter kualitas air  (BOD5, N-NO3, P-PO4, EC, dan TC) di SB, berturut-turut, sebesar 0.317 mg/l, 0.093 mg/l, 2 mg/l, >2420 MPN, dan >2420 MPN; di SM, berturut-turut, sebesar 0.029 mg/l, 1.859 mg/l, 17.7 mg/l, >2420 MPN, dan >2420 MPN; dan di ST, berturut-turut, sebesar 0.299 mg/l, 0.252 mg/l, 3.5 mg/l, >2420 MPN, dan >2420 MPN. Konsentrasi kualitas air ketiga sungai tersebut tidak berbeda secara signifikan (p>0.05), kecuali parameter N-NO3 (p<0.01). Secara umum, kondisi kualitas air ketiga sungai tersebut, menurut Peraturan Pemerintah No. 82, 2001) berada dalam status “tidak cocok” untuk peruntukannya.



Author(s):  
Betina Nørgaard Pedersen ◽  
Bent T. Christensen ◽  
Luca Bechini ◽  
Daniele Cavalli ◽  
Jørgen Eriksen ◽  
...  

Abstract The plant availability of manure nitrogen (N) is influenced by manure composition in the year of application whereas some studies indicate that the legacy effect in following years is independent of the composition. The plant availability of N in pig and cattle slurries with variable contents of particulate matter was determined in a 3-year field study. We separated cattle and a pig slurry into liquid and solid fractions by centrifugation. Slurry mixtures with varying proportions of solid and liquid fraction were applied to a loamy sand soil at similar NH4+-N rates in the first year. Yields and N offtake of spring barley and undersown perennial ryegrass were compared to plots receiving mineral N fertilizer. The first year N fertilizer replacement value (NFRV) of total N in slurry mixtures decreased with increasing proportion of solid fraction. The second and third season NFRV averaged 6.5% and 3.8% of total N, respectively, for cattle slurries, and 18% and 7.5% for pig slurries and was not related to the proportion of solid fraction. The estimated net N mineralization of residual organic N increased nearly linearly with growing degree days (GDD) with a rate of 0.0058%/GDD for cattle and 0.0116%/GDD for pig slurries at 2000–5000 GDD after application. In conclusion NFRV of slurry decreased with increasing proportion of solid fraction in the first year. In the second year, NFRV of pig slurry N was significantly higher than that of cattle slurry N and unaffected by proportion between solid and liquid fraction.



Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.



Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1477
Author(s):  
Antonio Marín-Martínez ◽  
Alberto Sanz-Cobeña ◽  
Mª Angeles Bustamante ◽  
Enrique Agulló ◽  
Concepción Paredes

In semi-arid vineyard agroecosystems, highly vulnerable in the context of climate change, the soil organic matter (OM) content is crucial to the improvement of soil fertility and grape productivity. The impact of OM, from compost and animal manure, on soil properties (e.g., pH, oxidisable organic C, organic N, NH4+-N and NO3−-N), grape yield and direct greenhouse gas (GHG) emission in vineyards was assessed. For this purpose, two wine grape varieties were chosen and managed differently: with a rain-fed non-trellising vineyard of Monastrell, a drip-irrigated trellising vineyard of Monastrell and a drip-irrigated trellising vineyard of Cabernet Sauvignon. The studied fertiliser treatments were without organic amendments (C), sheep/goat manure (SGM) and distillery organic waste compost (DC). The SGM and DC treatments were applied at a rate of 4600 kg ha−1 (fresh weight, FW) and 5000 kg ha−1 FW, respectively. The use of organic amendments improved soil fertility and grape yield, especially in the drip-irrigated trellising vineyards. Increased CO2 emissions were coincident with higher grape yields and manure application (maximum CO2 emissions = 1518 mg C-CO2 m−2 d−1). In contrast, N2O emissions, mainly produced through nitrification, were decreased in the plots showing higher grape production (minimum N2O emissions = −0.090 mg N2O-N m−2 d−1). In all plots, the CH4 fluxes were negative during most of the experiment (−1.073−0.403 mg CH4-C m−2 d−1), indicating that these ecosystems can represent a significant sink for atmospheric CH4. According to our results, the optimal vineyard management, considering soil properties, yield and GHG mitigation together, was the use of compost in a drip-irrigated trellising vineyard with the grape variety Monastrell.



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