C. Compost Use as Mulches

Favorable surface soil conditions under mulch without tillage can encourage root

branching and root growth in surface layers (Richards, 1983; Van Huyssteen, 1988).

Clippings (from alley swards during mowing), straw, bark, or plastic film can serve

as effective mulches in fruit production systems. However, organic mulches are not

commonly used for soil management in orchards. Clean cultivation and chemical

weeding are more common practices used in fruit production systems because they

provide effective and economical weed control. Concerns have been raised about

the environmental and agronomic impacts of clean cultivation and herbicide use,

such as soil structure decay, erosion, interaction with soil biological activity (microorganisms, earthworms), flora replacement, and pollution of groundwater (Boubals,

1991; Mantinger, 1990). Plastic mulch also is reported to be effective in weed control

and of benefit to the vegetative and reproductive development of fruit crops (Pool

et al., 1990; Van Der Westhuizen, 1980).

Compost, if used as a mulch, should be applied along the row of fruit trees, 5

cm thick and 50 cm wide. Composts with a minimum level of maturation, as long

as sufficiently stabilized, with large particle sizes (sieve diameter 20 to 30 mm), and

without viable weed seeds can be effective as mulches. Composts as mulches last

for 2 to 3 years, after which a repeated application is needed. Composts or mulches

are of benefit in maintenance dressing of fruit production systems because they can

restore nutrients removed by fruit trees, particularly during the reproductive stages,

without the use of inorganic fertilizers (Pinamonti et al., 1991).

Compost rates necessary to obtain effective mulching vary according to the

planting arrangement. For example, a strip of mulch 50 cm wide and 5 cm thick

with rows spaced at 5, 4, 3, and 2 m, requires compost (bulk density 0.5 kg·L–1)

rates of 25, 31, 42, and 62 t·ha–1, respectively.

Erosion has been aggravated in vineyards located on hilly slopes of France due

to parcel extension with removal of natural obstacles (green covered headland, dry

walls, hedges, rows of trees), increase in the traffic of vineyard machinery, and more

herbicide usage (Delas, 1989). Organic mulching is a suitable technique to control

soil surface erosion. Besides physically covering the soil, organic mulches can

improve water-retention capacity, increase effective water infiltration, and provide

reliable water runoff control (Delas, 1989). MSW compost has been effective in

reducing soil erosion in Champagne vineyards with a no-tillage system for 20 years

(Delas, 1989).

Composts utilized as mulches can be applied at rates varying from 90 to 120

t·ha–1 in the first year and then at rates varying from 40 to 60 t·ha–1 every 3 to 4

years. The effectiveness of composts as mulches in fruit production systems has

been reported (Ballif and Herre, 1988; Carsoulle et al., 1986). Water runoff and soil

losses were reduced from clay-calcareous soil with a slope of 34% with MSW

compost applications (Table 8.6) (Ballif and Herre, 1988). Similar results were noted

in grapevine plots with a rotating rainfall simulating system (Carsoulle et al., 1986).

When applied to eroded soils, compost can restore both organic matter content and

soil structure (Kashmanian et al., 1990). However, compost mulch does not change

the qualitative characteristics of enologic products (Sauvage, 1995).

In Italy, fruit and viticulture crops are grown on about 2 million hectares and

often are cultivated on hilly areas, with low fertility and low soil organic matter

© 2001 by CRC Press LLC



Table 8.6 Effects of Soil Mulching by MSW Compost on Water Runoff and Soil Lossesz

Treatment

Water runoff (mm)

Water runoff resulting from storm

rainfalls (mm)

Soil losses (kg·ha–1)



Control

(Untilled and Bare Soil)



MSW Compost Mulch

(150 t·ha–1)



11.8

10.0–22.0



1.2

2.2–1.6



1382



5.3



z



MSW = municipal solid waste.

From Ballif, J.L. and C. Herre, 1988. Contribution a l’étude de ruissellment de sols viticoles in

Champagne. Effects d’une couverture de compost urbain. Comptes Rendus de l’Académie

d’Agriculture de France 74:108. With permission.



content. The under row strips are periodically cultivated or herbicides are applied

to control weeds (Fregoni and Miravalle, 1991).

In new vineyards, mulching with compost was compared with black polyethylene

mulching and a control (mechanical tillage and chemical weeding) (Pinamonti,

1998a; Pinamonti et al., 1996; Pinamonti et al., 1991). Soil moisture content of

compost mulched plots was consistently higher than in the control or polyethylene

mulched plots (Figure 8.1). Compost mulches improved water permeability and

water storage and reduced water evaporation. Polyethylene mulch prevented water

infiltration, but reduced surface evaporation. Compost mulches reduced daily and

seasonal low and high temperature fluctuations, whereas the polyethylene resulted

in extreme soil temperatures fluctuations (Figures 8.2 and 8.3).



Figure 8.1



Soil moisture content (20 cm depth) in the grapevine row as influenced by mulches

in a vineyard. (From Pinamonti, F., 1998a. Compost mulch effects on soil fertility,

nutritional status and performance of grapevine. Nutrient Cycling in Agroecosystems 51:242. With permission.)



© 2001 by CRC Press LLC



Figure 8.2



Soil temperature (20 cm depth) in the grapevine row as influenced by mulches in

a vineyard. (From Pinamonti, F., 1998a. Compost mulch effects on soil fertility,

nutritional status and performance of grapevine. Nutrient Cycling in Agroecosystems 51:242. With permission.)



Figure 8.3



Soil temperature measured on 18 August 1990 (20 cm depth) in the grapevine

row as influenced by mulches in a vineyard. (From Pinamonti, F., 1998a. Compost

mulch effects on soil fertility, nutritional status and performance of grapevine.

Nutrient Cycling in Agroecosystems 51:243. With permission.)



© 2001 by CRC Press LLC



Table 8.7 Chemical and Physical Properties of Soils as Affected by Mulching with

Polyethylene and with Compost



Mulchesz



Control

PE

BB

compost

MSW

compost



pH



Water

Organic

N

Available

Stability

Matter Kjeldahl

P

K

Mg

Water

Porosity Index

(%)

(%)

(mg·kg–1) (mg·kg–1) (mg·kg–1)

(%)

(% Vol)

(%)



7.58 2.67 by

7.62 2.63 b

7.60 3.12 a



0.160 b

0.155 b

0.181 a



30.7 b

28.9 b

38.6 a



176 b

177 b

215 a



203

191

207



12.4 b

12.3 b

13.5 a



43.5 b

43.1 b

45.2 a



34.7 b

33.3 b

41.1 a



7.61 3.08 a



0.177 a



40.1 a



206 a



212



13.1 a



44.8 a



35.7 b



Note: The values are means of 1990–1995.

PE = black polyethylene plastic film (0.12 mm thick) applied immediately after grapevine planting;

BB = biosolid/bark; MSW = municipal solid waste.

y Means followed by the same letter are not statistically different (Duncan multiple range test, P ≤

0.05).

From Pinamonti, F., 1998a. Compost mulch effects on soil fertility, nutritional status and performance

of grapevine. Nutrient Cycling in Agroecosystems 51:243. With permission.

z



Weed growth was reduced by compost mulch to a similar level of the control

(mechanical tillage and chemical weeding). The weed control provided by the

compost mulch diminished during the first growing season, but the compost mulch

still allowed a reduction in the number of herbicide applications. The polyethylene

film controlled weeds up to the sixth year.

Compost mulch increased organic matter content, total N, available P, exchangeable K, available water content, and porosity of the soil compared to the polyethylene

or control plots (Table 8.7). Compost mulch plots had more root growth near the

soil surface and more root exploration of the topsoil than polyethylene or control

plots. Leaf analysis of grapevines showed that compost mulch increased concentrations of K and decreased concentrations of P, Ca, and Mg (Table 8.8). Leaf concentrations of N, Fe, or Mn remained unchanged throughout the trial.

Table 8.8 Grape Leaf Nutrient Concentration for Soil Mulched with

Polyethylene and with Composts (Dry Weight Basis)

Mulchesz



N

(%)



P

(%)



Control

PE

BB compost

MSW compost



2.59

2.61

2.58

2.57



0.157

0.157

0.143

0.148



K

(%)

ay

a

b

b



1.31

1.30

1.39

1.41



Ca

(%)

b

b

a

a



2.18

2.17

2.07

2.09



Mg

(%)

a

a

b

b



0.313

0.309

0.287

0.297



Fe

Mn

(mg·kg–1) (mg·kg–1)

a

a

b

ab



89.1

90.3

96.2

89.8



175

178

175

162



Note: Values are means of 1990–1995.

z PE = black polyethylene plastic film (0.12 mm thick) applied immediately after

grapevine planting; BB = biosolid/bark; MSW = municipal solid waste.

y Means followed by the same letter are not statistically different (Duncan multiple

range test, P ≤ 0.05).

From Pinamonti, F., 1998a. Compost mulch effects on soil fertility, nutritional status

and performance of grapevine. Nutrient Cycling in Agroecosystems 51:244. With

permission.



© 2001 by CRC Press LLC



Table 8.9 Influence of Mulching with Polyethylene and with Compost on Pruning

Weight from Grapevines and Grape Yields

Mulchesz

Control

PE

BB compost

MSW compost



1990

10.9

36.8

26.2

23.6



cy

a

b

b



Pruning Weight (g/vine)

Yield of Grapes (kg/vine)

1991 1992

1993 1994 1995 1992 1993 1994 1995

111 b

136 a

78 c

98 bc



186

194

165

175



ab

a

c

bc



421

450

363

402



ab

a

c

bc



248

241

256

241



265

258

271

256



0.94

1.09

0.91

1.13



b

a

b

a



3.33

4.09

3.11

2.84



ab

a

b

b



1.93

2.16

2.06

2.33



2.14

2.58

2.19

2.09



b

a

b

b



z



PE = black polyethylene plastic film (0.12 mm thick) applied immediately after grapevine

planting; BB = biosolid/bark; MSW = municipal solid waste.

y Means followed by the same letter are not statistically different (Duncan multiple range

test, P ≤ 0.05).

From Pinamonti, F., 1998a. Compost mulch effects on soil fertility, nutritional status and

performance of grapevine. Nutrient Cycling in Agroecosystems 51:244. With permission.



The number of dead vines on compost mulch plots at the end of the first

vegetative season was 1 to 2% lower than in the control (3.9%) or polyethylene

mulch (8.5%) plots. Grapevines from compost mulch plots had improved general

performance and plant growth during the first years. Pruning weights of vines in

compost-mulched plots were 120 to 140% higher than in control plots after the first

year. However, these differences decreased with time, despite additional compost

applications at the beginning of the fourth year (Table 8.9).

Compost mulch did not cause differences in qualitative characteristics of the

musts compared to the control, except for slight changes in the acidic balance.

Pinamonti and Zorzi (1996) and Pinamonti (1998b) reported similar results with

apple trees. Generally, more favorable effects of mulching with compost occur on

vineyards than apple orchards due to the lower organic matter content in vineyard

soils than in apple orchard soils. Other studies confirm that compost mulch improves

the development of young fruit trees or young vines in the establishment years and

results in earlier maximum yields (Fujiwara, 1996; Pinamonti and Zorzi, 1996).

Improved soil moisture content has been reported with the use of compost mulch.

Pinamonti (1998a) reported that the soil moisture content in compost mulch plots

was higher than in control plots. This is attributed to the permeability capacity of

the compost layer that allows water storage in the soil with minimal water losses

by evaporation. The compost mulch layer has an insulation effect that reduces diurnal

fluctuations in soil temperature (Hartley and Rahman, 1994).

Fujiwara (1996) reported that weed growth within rows of vineyards was

restricted for a few months (one vegetative season) after compost mulch was applied.

However, herbicides are eventually required even on the mulched strip (Moncomble

and Descotes, 1992).

Leaf samples from grapevine and apple plots with compost mulch had higher P

and reduced K, Ca, and Mg contents than control plots. The nutritional changes

were partially attributed to changed soil conditions (moisture and temperature) and

a diversified root structure that grew less in depth due to mulching (Pinamonti et

al., 1996; Walsh et al., 1996). Compost mulch in viticulture, together with a system



© 2001 by CRC Press LLC



of partial fertilization and surface tillage, stimulated root growth, improved fruit

color, and increased fruit weight and sugar content (Fujiwara, 1996).

Compost mulch was reported to increase total CO2 emission in the field and

cellulose degradation activity (Hartley et al., 1996), and to improve earthworm

activity (Hartley and Rahman, 1994). Agassi et al. (1998) reported that 85% of

rainwater percolated into the soil in compost mulched plots as compared with 42%

in the control plots. Compost mulch stimulated both enzymatic activity (dehydrogenase and fluorescein diacetate) and soil microbial activity.

Compost mulch has beneficial effects on soil fertility (higher content of organic

matter and improvement of physical properties); therefore it is a viable alternative

to inorganic fertilizers used for maintenance dressing in fruit production systems.

The nutrients contained in compost are released slowly (Sikora, 1996), thereby

preventing physiological nutrient imbalances in vines and fruit trees or reduction in

product quality. Application of composts as mulches can improve water balance and

thermal conditions of soils resulting in more vegetative development of young fruit

trees or young vines in the establishment phase. However, over an extended time,

compost as mulch did not have significant effects on the nutritive, vegetative, or

reproductive status of fruit trees or grapevines. The agronomic beneficial contribution

from composts as mulches occurs during the establishment years of young orchards.

However, compost applications improve soil fertility, reduce erosion, and can be a

partial substitute for inorganic fertilizers (Sikora, 1996).

D. Compost Application into Planting Holes

Grafted trees with bare roots are generally used to establish orchards. When

saplings or young trees are planted, soils in planting holes should be managed to

optimize root development and vegetative growth. Planting holes are generally filled

with fresh soil but may have an application of 5 to 10 L of peat per hole. Orchards

that are renovated with the same species (monocultural succession cropping) utilize

these same soil management practices for plant establishment, primarily to reduce

potential fruit tree replant problems (Zucconi and Monaco, 1987).

Organic amendments (composts) applied in planting holes should be highly

stabilized, have low concentrations of soluble salts (electrical conductivity less than

2000 µS·cm–1), be free of phytotoxic compounds, and have optimum particle size

(screened through 10 mm diameter sieve). These compost attributes are especially

important since the material has intimate contact with the root system. Compost

should also have a moisture content between 35 to 50% (Epstein, 1997). Compost

with a high moisture content is expensive to transport and difficult to handle.

Compost that is very dry is dusty, does not imbibe water effectively, and can induce

water stress to the tree upon planting (Pinamonti, 1998a).

In Italy, biosolid/bark compost, MSW compost, and peat were evaluated as

amendments in planting holes (5 L per hole, 5 to 20 t·ha–1) for six apple cultivars

(Table 8.10) (Pinamonti and Zorzi, 1996). After 4 years, apple shoot radius and

yields were similar between MSW compost and untreated control plots (Table 8.10).

However, biosolid/bark compost and peat amendments increased both growth and

yield of apples compared to the control (Table 8.10). Perhaps the high pH and soluble

© 2001 by CRC Press LLC



Table 8.10



Influence of Compost in Planting Holes on Vigor and Yield of

Apple Trees



Amendment and Ratez



1989



Control

Peat (5 L/tree)

BB compost (5 L/tree)

MSW compost (5 L/tree)



1.76 by

1.88 a

1.86 a

1.78 b



Shoot Radius (cm)

1990

1991

2.73

2.83

2.85

2.71



b

a

a

b



3.54

3.66

3.68

3.52



b

a

a

b



1992



Yield (kg/tree)

1991

1992



4.33

4.36

4.41

4.29



3.63

4.36

4.18

3.60



b

a

a

b



8.69

9.73

9.97

8.09



b

a

a

c



Note: Values are means of six trials.

z BB = biosolids/bark; MSW = municipal solid waste.

y Means followed by the same letter are not statistically different (Duncan multiple

range test, P ≤ 0.05).

From Pinamonti, F. and G. Zorzi, 1996. Experiences of compost use in agriculture

and in land reclamation projects, p. 520. In: M. De Bertoldi et al. (eds.). The Science

of Composting, Part 1. Blackie Academic and Professional, London. With permission.



salt content of the MSW compost contributed to the lack of a beneficial response.

Improved growth responses were reported with annual applications of compost in

mound-layered trees for the production of apple rootstocks in comparison to peat

and rice (Oryza sativa L.) chaff (Pinamonti, 1998b). Compost applications in citrus

(Citrus spp.) planting holes also can reduce the presence of Phytophthora nicotianae

both in the nursery and in the field (Widmer et al., 1998).



IV. CONCLUSION

Compost utilization in fruit production systems as a soil organic amendment

increases organic matter content, supplies nutrients, and improves soil physical

properties. The use of compost alone is not sufficient to meet crop nutritional

requirements. Therefore, compost integrated with reduced rates of inorganic fertilizers may be an effective alternative to improve infertile soils used for fruit culture.

In fact, mixed compost/inorganic fertilizer applications are not only complementary

but also synergistic since soil organic amendments provide a greater efficiency of

inorganic fertilizers and irrigation water for plant nutrient availability. In fruit production systems, compost provides a slow and gradual release of nutrients that does

not induce excessive vegetative growth or reduce fruit quality.

Mulching with compost in orchards improves soil water balance and soil physical

properties, reduces erosion, and allows decreases in inorganic fertilizer rates.

Compost applied both in corrective dressing (before planting) and in planting

holes can reduce fruit tree replant problems associated with monocultural succession

cropping, and thus can serve as an alternative to fruit crop rotation.

Compost has been used as an alternative and/or complement to traditional cow

manure application in fruit production systems. Numerous trials have shown the

potential advantages following application of compost as a soil organic amendment

(Table 8.11). However, some precautions are necessary when compost is utilized in

fruit production systems. Key factors to be considered are compost compatibility

with plants (phytotoxicity) and effects on soil fertility. Compost should be free of

© 2001 by CRC Press LLC