Fertigation: Optimizing the Utilization of Water and Nutrients - SSWM

More documents

Recommendations

Info

Fig. 2. Schematic representation of ROS formation in chloroplasts under environmental stress conditions.: indicates inhibition of the corresponding reaction by stress. (Cakmak, 2003, 2005). Nitrogen Of the mineral nutrients, nitrogen plays a major role in utilization of absorbed light energy and photosynthetic carbon metabolism (Kato et al., 2003; Huang et al., 2004). An excess of non-‐utilized light energy can be expected to occur in N-‐deficient leaves, where it leads to a high risk of photo-‐oxidative damage. In rice plants under high light intensity, N deficiency is associated with enhanced lipid peroxidation (Huang et al., 2004), and Kato et al. (2003) recently showed that plants grown under high-‐intensity light with a high N supply had greater tolerance to photo-‐oxidative damage and higher photosynthesis capacity than those grown under similar high light with a low N supply. Utilization of the absorbed light energy in electron transport was also much higher in N-‐adequate than in N-‐deficient plants. These results indicate that N-‐adequate plants are able to tolerate excess light by maintaining photosynthesis at high rates and developing protective mechanisms. To avoid the occurrence of photo-‐oxidative damage in response to excess light energy, the thylakoid membranes have a protective mechanism by which excess energy is dissipated as heat. Dissipation of excess light energy is associated with enhanced formation of the xanthophyll pigment zeaxanthin, which is synthesized from violaxanthin in the light-‐ dependent xanthophyll cycle (Demmig-‐Adams and Adams, 1992, 1996): 38
Violaxanthin high light low light Antheraxanthin high light low light Zeaxanthin In plants suffering from N deficiency, the conversion of xanthophyll cycle pigments and formation of zeaxanthin were enhanced, and were accompanied by chlorophyll bleaching, particularly under high light intensity (Verhoeven et al., 1997; Kato et al., 2003). In spinach, N-‐deficient plants dissipate a greater fraction of the absorbed light energy than N-‐adequate ones: up to 64% and only 36%, respectively. This difference was associated with corresponding changes in xanthophyll cycle pigments: about 65% of the total xanthophyll pigments were present as zeaxanthin and antheraxanthin in N-‐deficient plants compared with 18% in the N-‐adequate plants (Verhoeven et al., 1997). These results indicate impaired use of the absorbed light energy in photosynthetic fixation of CO2, with consequently enhanced demand for protection against excess light energy, in N-‐deficient plants. Certainly, the reduction in the utilization of light energy and the consequently elevated need for protection against photo-‐ oxidative damage in N-‐deficient plants can be more marked when the N deficiency stress is combined with an environmental stress. The form in which N is supplied affects plant tolerance to photodamage. The light-‐induced conversion of violaxanthin to zeaxanthin, as a means to dissipate excess light energy was found to be stronger in bean leaves supplied with nitrate than in those supplied with ammonium (Bendixen et al., 2001). In good agreement with these findings, Zhu et al. (2000) demonstrated that nitrate-‐ grown bean plants had higher tolerance to photodamage than ammonium-‐grown ones. Under very high light intensity ammonium-‐grown plants had, therefore, higher levels of lipid peroxidation and higher contents of antioxidative enzymes. Potassium, magnesium and zinc Similarly to N deficiency, deficiencies of K, Mg and Zn also enhance the sensitivity of plants to photo-‐oxidative damage. When supplies of these nutrients are low, leaf symptoms of chlorosis and necrosis, and disturbances of plant growth become more severe when plants exposed to high light intensity (Marschner and Cakmak, 1989; Cakmak and Marschner, 1992; Cakmak et al., 1995; Polle, 1996). 39
Page 1 and 2: Fertigation Proceedings: Selected P
Page 3 and 4: © All rights held by: Internationa
Page 5: Yield and Fruit Quality of Tomato a
Page 8 and 9: Preface Irrigation is a crucial com
Page 10 and 11: Global Aspects of Fertigation Usage
Page 12 and 13: 5. 6. 7. Prevents salt injuries to
Page 14 and 15: Fertigation reduces the amount of h
Page 16 and 17: Fertilizer delivery There are two m
Page 18 and 19: concentration can result in ammonia
Page 20 and 21: Scheduling fertigation Nutrient ele
Page 22: soil temperatures are high, i.e., u
Page 25: Kafkafi, U. 1994. Combined irrigati
Page 29 and 30: Introduction The rapid economic dev
Page 31 and 32: However, small changes in the assum
Page 34 and 35: and industrial feedstocks (Table 1)
Page 36: Environmentally sound nutrient mana
Page 39 and 40: fertilizers also show promise for i
Page 41: Matson, P., P. Loiseau, and S.J. Ha
Page 45: minimizing detrimental effects of e
Page 50: Deficiencies of K and/or Mg cause m
Page 53: nutritional status of the plants. T
Page 56 and 57: Conclusions The existing data indic
Page 59: Close, D.C., C.L. Beadle, and M.J.
Page 63: Wang, Y.J., M. Wisniewski, R. Melia
Page 66 and 67: strongly for potable water, but whi
Page 68 and 69: In Asia, 84% of the water is used f
Page 71 and 72: Discussion Value of nutrients in TW
Page 73 and 74: sources are presented in Table 3. T
Page 75 and 76: Fig. 4. P concentration in soil pro
Page 77: Cornel, P. ,and B. Weber. 2004. Wat
Page 80 and 81: Introduction “Fertigation” is a
Page 82 and 83: Young bearing trees Thompson et al.
Page 85 and 86: Fig.3. Effects of fertilizer source
Page 87 and 88: (TSS) yield was 16% greater with fe
Page 89 and 90: surficial aquifer underneath citrus
Page 91 and 92: Fig. 8. Comparison of the effects o
Page 93 and 94: Fig. 10. Fruit yield responses (6-
Page 96 and 97: Fertigation of Deciduous Fruit Tree
Page 98 and 99:
demand more precisely than in syste
Page 101:
In sandy soils, it is also possible
Page 104 and 105:
supplied N at about 63 kg/ha, indic
Page 106 and 107:
Phosphorus Fertigation is known to
Page 108 and 109:
Conclusions Fertigation offers the
Page 111:
Neilsen, D., P. Millard, L.C. Herbe
Page 114 and 115:
consumed as table grapes, 16% are d
Page 117 and 118:
Table 1. Estimates of approximate p
Page 119 and 120:
affected by rootstock (Treeby et al
Page 121 and 122:
The table grape fertigation decisio
Page 123 and 124:
References Alexander, D. McE. 1957.
Page 126:
Henschke, P.A., and V. Jiranek. 199
Page 130:
Zerihun, A., and M.T. Treeby. 2002.
Page 133 and 134:
integration of this knowledge into
Page 135 and 136:
Table 1: Concentrations of macro-
Page 137:
y moderate application rates (maxim
Page 140 and 141:
Fig. 7. Outgrowth but not the numbe
Page 142 and 143:
scarcity, micro-‐irrigation sys
Page 145 and 146:
Conclusions The presented case stud
Page 148 and 149:
Fertigation in Greenhouse Productio
Page 150 and 151:
Table 2. Target values for nutrient
Page 152 and 153:
Table 4. Water and nitrogen efficie
Page 154 and 155:
quantity and quality is therefore s
Page 157 and 158:
To control the model, the moisture
Page 159 and 160:
(1) (2) Table 6. Results of a 3-
Page 161 and 162:
References Adams, P. 1991. Effects
Page 164 and 165:
Effects of Fertigation Regime on Bl
Page 166 and 167:
incidence of BER in pepper fruits (
Page 168 and 169:
eported an increase in the incidenc
Page 170 and 171:
oth the fruits and the young leaves
Page 173 and 174:
The use of the ECS reduced the inci
Page 175 and 176:
Fig. 5. The effects of Mn on the Na
Page 177:
Bar-‐Tal, A., and E. Pressman.
Page 181:
Maynard, D.N., W.S. Barham, and C.L
Page 185:
Fertigation in Micro-‐irrigated
Page 189 and 190:
other irrigation systems. These hig
Page 191 and 192:
secondary elements, and micro-‐
Page 193 and 194:
supplied by applying part of the fe
Page 196:
Locascio, S.J., and J.M. Myers. 197
Page 200 and 201:
Yield and Fruit Quality of Tomato a
Page 202 and 203:
Table 1. Effects of K:Ca ratios on
Page 204:
Munson, R.D. 1985. Potassium in Agr
Page 207 and 208:
nutrients, and certain species are
Page 209 and 210:
via drip lines with a dripper for e
Page 211:
Prior to the start of the greenhous
Page 214:
Both Chlamydomonas spp. and Scenede
Page 217:
Ravina, I., E. Paz, Z. Sofer, A. Ma
Page 220 and 221:
common methods of irrigation includ
Page 223 and 224:
then be used to describe crop water
Page 226 and 227:
In aiming to optimize fertigation e
Page 228 and 229:
Interactive Effects of Nutrients an
Page 230 and 231:
nutrient levels, especially when th
Page 232:
supply will not improve plant growt
show all

Fertigation: Optimizing the Utilization of Water and Nutrients - SSWM

Create successful ePaper yourself

Delete template?

Save as template?