Influence of farmyard manure application (1)

Scientia Horticulturae 164 (2013) 414–427

Contents lists available at ScienceDirect

Scientia Horticulturae

journal h om epa ge: www.elsevier.com/locate/scihorti

Influence of farmyard manure application and mineral fertilization on

yield sustainability, carbon sequestration potential and soil property of gardenpea–french bean cropping system in the Indian Himalayas

Dibakar Mahanta a , ∗ , R. Bhattacharyya b , K.A. Gopinath c , M.D. Tuti a , Jeevanandan K a , Chandrashekara C a , Arunkumar R a , B.L. Mina a , B.M. Pandey a , P.K. Mishra a , J.K. Bisht a ,

A.K. Srivastva a , J.C. Bhatt a

a Vivekananda Institute of Hill Agriculture (Indian Council of Agricultural Research), Almora 263 601, Uttarakhand, India

b Indian Agricultural Research Institute, New Delhi 110 012, India

c Central Research Institute for Dryland Agriculture, Santoshnagar, Saidabad , Hyderabad 500 059, India

Article history: Sustainability of agricultural systems has become an important issue all over the world. Hence, sustaina-

Received 14 April 2013 bility and climate resilience of gardenpea–french bean cropping system was evaluated by yield trends, C

and soil

Received in revised form 23 August 2013 sequestration and emission reduction

properties as affected by four application rates of farmyard

Accepted 3 October 2013 manure (FYM) (5–20 t ha − 1 ) vis-à-vis mineral fertilization, integrated nutrient management (INM) prac-

tices as 50% recommended NPK + FYM at 5 t ha − 1 and un-amended control after six years of cropping in

Keywords: the Indian Himalayas. The highest sustainable yield index of 0.606 was achieved with the application of Carbon sequestration potential

20 t FYM ha − 1 (FYM 20 ). The Farmyard sequestration potential of manure carbon FYM 20 plots was about 459 and 193% more

Soil cation exchange capacity than NPK and INM plots, respectively. The same plots reduced 53 and 24% carbon equivalent emission

Soil cracking with comparison to NPK and INM application, respectively. The soil cation exchange capacity (CEC) under

Soil temperature FYM 20 plots was 22 and 11% higher than NPK and INM plots. The soil cracking volume under FYM 20 plots Sustainable yield index. (57 cm 3 m − 2 area) was very less compared to NPK (324 cm 3 m − 2 area) and INM (154 cm 3 m − 2 area) plots.

The morning soil temperature (0–15 cm depth) in coldest week of last year experimentation under FYM 20 plots was moderated by 0.60 and 0.47 ◦ C than NPK and INM plots, respectively. Successive increase of

FYM level improved soil organic C, microbial colony formation unit, dehydrogenase activity, bulk den-

sity and soil cracking surface area and the best values for all soil properties were recorded under FYM 20 plots. Application of 20 t FYM ha − 1 produced 54 and 29% higher gardenpea equivalent pod yield of the

system than mineral fertilization and INM, respectively. The principal component analysis revealed that

soil CEC was the most important property (among the selected soil parameters) contributing to the pod

yield. Soil organic carbon markedly improved other soil properties as evident from correlations. Organic

production system with FYM 20 t ha − 1 could be recommended for climate resilient sustainable yield and

better soil property of gardenpea–french bean cropping system than mineral fertilization and INM in the

Indian Himalayan regions.

© 2013 Elsevier B.V. All rights reserved.

1. Introduction of environmental degradation, including air and water pollution,

soil depletion and diminishing biodiversity and soil quality. Again

Adoption of recent agricultural practices involves off-farm or the increase in extreme climatic variability in the Indian Himalayan

external chemical inputs which release CO 2 and other green house regions ( Panday et al., 2009 ) is adding uncertainty of agricultural

gases (GHGs) to atmosphere during production, transportation and productivity. Hence, sustainability of agricultural systems with low

storage. Industrial agriculture inputs contribute to numerous forms or without emission of GHGs has become an important issue all over

the world. Conversely, organic source may influence agricultural

sustainability by improving soil quality ( Saha et al., 2008 ). Organic

farming is increasingly becoming popular because of the perceived

health and environment benefits ( Zhao et al., 2009 ). Several cil of Agricultural Research), Almora 263 601, Uttarakhand, studies

∗ Corresponding author at: Vivekananda Institute of Hill Agriculture (Indian Coun-

India. Tel.: +91 5962 241005; fax: +91 5962 241250. have reported lower yields in organic conditions with comparison

E-mail address: dibakar mahanta@yahoo.com (D. Mahanta). to mineral fertilizations ( Astier et al., 1994; Gopinath et al., 2009;

0304-4238/$ – see front matter © 2013 Elsevier B.V. All rights reserved.

http://dx.doi.org/10.1016/j.scienta.2013.10.002

D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427 415

Liebhardt et al., 1989; MacRae et al., 1990 ). Initially lower yields Table 1

on organic farms have been attributed to the negative effects of Physical and chemical properties of farmyard manure (mean of six years).

conventional practices on the soil microorganisms that mineralize Particulars Characteristics soil organic matter, or that control soil-borne pests ( Martini et al., Color Brownish black

2004 ). But, these organic systems may lead to more biological activ- Basic organic material Cattle dung and urine + left-over

ity and improve soil quality than industrial conventional systems material of fodder + litter

Small

( Castillo and Joergensen, 2001; Fliessbach et al., 2007; Garcia-Ruiz Texture lumps

3 et a al., 2008; Gopinath et al., 2009 ). Nutrient management is, there- Bulk density (Mg m )

critical 376 management kg practices for organic

fore, one of the most Water holding capacity (g

pH c

7.76 kg ) 299

growers.

Organic carbon (g − 1

In the past five decades, the traditional knowledge and prac- N (g kg − –1 )

10.16 tices of organic farming have been almost eroded from many parts P (g kg 1 ) 5.04

− 1 of India due to influx of modern “green revolution” technologies K (g kg )

7.81 C:N ratio 29:1

( Gopinath et al., 2009 ). However, for many farmers (especially small

and marginal) in a

Himalayas, the purchase of manufactured fertil- b Oven dry-weight basis.

− izers and pesticides is and will Water holding capacity was the difference of moisture content between continue 0.33 to be constrained by their and − 15 bar pressure.

high costs and unavailability. Furthermore, use of locally avail- c FYM:Moisture = 1:5.

able natural resources and farmers’ knowledge are far more likely

to meet the needs and aspirations of resource-poor farmers than ◦ those ′ that

require costly or scarce external inputs ( Parrott et al., located in the Indian Himalayan region at Hawalbagh (29 36 N and 79 ◦ 40 ′ E and 2006 ). The world organic is considered to cover 1250 production system m above mean sea level) in the state of

an area of 37 million hectares in 162 different countries with 1.8 Uttarakhand, India. The soil was silty clay loam (Typic Haplaquept)

with the following characteristics in 0–15 cm million producers and the world organic market is estimated at depth: pH 6.1 more than 62.9 billion US dollars in 2011 ( Willer et al., 2013 ). This (1:2.5 soil:water suspension), easily oxidizable (K 2 Cr 2 O 7 + H 2 SO 4 )

organic market expansion makes it possible for Himalayan farmers organic C 11.3 g kg − 1 , alkaline KMnO oxidizable N 179.9 mg kg 4 − 1 , to emerge as major suppliers of organic products with high price 0.5 M NaHCO 3 extractable P 6.79 mg kg − 1 and 1.0 N NH 4 OAc

premiums ( Gopinath et al., 2009 ). Again the per capita livestock exchangeable K 80.4 mg kg − 1 soil.

population in Indian Himalayan states is very high than average The climatic conditions at the research farm indicates that the

of India ( Anonymous, 2012; Anonymous, 2011 ). This will help in extreme temperature condition is increasing i.e. minimum temper-

decreasing organic manures in these states and can fulfill the and maximum temperature is increasing over

producing more ature is

demand of organic manure for the organic producers to continue the years ( Panday et al., 2009; Panday et al., 2003 ). The frequency

of severe droughts astonishingly organic agriculture. The organic manures produced from livestock, increased from 1.39 to 3.75 years

if not utilized will add GHGs to the environment. out of 10 years ( Panday et al., 2009 ).

farmyard

Vegetable farmers in Indian Himalayas mostly apply The field

experiment consisted of seven treatments and was laid

manure (FYM) as nutrient source in organic cultivation. However, out in a randomized complete block design with three replications

in a fixed plot. The treatments were four rates of FYM level application there is limited research on the effects of application of higher i.e.

of FYM vis-à-vis mineral fertilization (recommended NPK only) and 5 t ha − 1 (FYM 5 ), 10 t ha − 1 (FYM 10 ), 15 t ha − 1 (FYM 15 ) and 20 t ha − 1 integrated nutrient management (INM; 50% of the recommended (FYM 20 ), mineral fertilization as recommended NPK (NPK), INM

NPK + 5 t FYM ha − 1 ) on yield of crops, sustainability of cropping

(50% recommended NPK as mineral fertilizer + FYM at 5 t ha − 1 ) system and soil quality (soil physical, chemical and biological prop- and unfertilized control. All organic amendments were applied

erties). Gardenpea and french bean are two important leguminous on a dry-weight basis. The nature and composition (physical and

vegetables cultivated in north-western Himalayas of India. Hence, chemical properties) of FYM were analyzed prior to incorpora-

tion into experimental plots and depicted in Table 1 we chose to evaluate the influence of FYM on gardenpea (Pisum . The mineral sativum var. hortense L.) and french bean (Phaseolus vulgaris L.) fertilizers in NPK and INM (recommended level: 20-26.2-33.3 kg N-

− 1 yield trends in the Indian Himalayas after six years of cropping. The P-K ha for gardenpea and 50-30.6-41.7 kg N-P-K ha for french hypothesis of the study were (i) Medium term (6 years) continu- bean) were applied at the sowing time and the sources for N, P

ous manure application under a year-round vegetable production and K were

urea, single superphosphate and muriate of potash,

system would store more C in soil and reduce emission of CO 2 and

respectively.

would have higher sustainable productivity compared with min-

eral fertilization and INM; (ii) Constant manuring would moderate 2.2. Yield data collection and sustainable yield index

winter and summer soil temperatures better than INM along with

improvement in soil property, thereby would have the potential At harvesting time, marketable green pods were picked in dif-

to adapt and mitigate the climate change impacts in the Indian ferent phases during the harvesting period for estimation of yield

Himalayas. The objectives of the study were (i) to find out the most parameters such as pod number per plant, pod length, and pod sustainable nutrient management practices for gardenpea–french yield (t ha − 1 ). Random samples of five plants were taken from

bean cropping system; (ii) to estimate the carbon sequestration

each plot for recording pod number plant − 1 and plant height.

potential of FYM and mineral fertilization and (iii) to assess the Pod numbers of these selected plants were counted by summing

effects of different levels of FYM vis-à-vis mineral fertilization and from first picking up to the last picking. Plant height was recorded

INM on selected soil properties. at the time of last picking of pods. Pod length was recorded by

averaging 20 pods in different pickings of selected five plants.

2. Materials and methods The pod yield of net plot size of 3.0 m × 3.0 m from gross plot

size of 3.6 m × 3.0 m was considered for estimation of pod yield

2.1. Experimental site and agronomic practices ha − 1 .

Observations were recorded on pod yield of gardenpea and

The field experiment was conducted during 2002–2008 at the french bean. The pod yield of french bean was converted into gar-

experimental farm of Vivekananda Institute of Hill Agriculture

denpea economic equivalent yield considering the market price of

416 D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427

week of the year. The coldest and hottest weeks were chosen on the

basis of mean of last six years atmospheric temperature. The morn-

ing temperature and afternoon temperature were recorded at 6:45

AM and 2:15 PM, respectively during coldest season week (January

second week) and at 5:00 AM and 2:15 PM, respectively during

hottest season week (22nd week of the year – May 27 to June 2).

The temperature difference of the day was calculated by subtrac-

ting morning temperature from the afternoon. The moderation of

soil temperature was estimated as difference of soil temperature

between treated and un-amended control plots during morning and afternoon for coldest and hottest week of year, respectively.

For determination of soil crack volume (SCV) and soil crack sur-

face area (SCSA), each experimental plot was divided into four parts

and squares of 1 m × 1 m were demarcated in each part. Within

each of these squares, crack length apparent on the soil surface

was measured by a flexible twine run along the crack and measur-

ing the total length of all the cracks in the 1 m × 1 m ( Dasog and

Shashidhara, 1993 ). The average depth and width of cracks were

Fig. 1. Weekly soil minimum and maximum temperature of last eight years from

based on

measurements made at 0.5 m interval along the course

the research farm of the experiment. of the crack. The crack depth was measured by a 2 mm diameter

steel rod inserted until it offered resistance to further penetration,

french bean and gardenpea as follows: while the width at the same point as that of depth recording was

Gardenpea economic equivalent yield of french bean measured with

an adjustable divider at 1 cm below the soil surface

( Dasog et al., 1988 ). A depth of 1 cm was chosen to avoid exagger-

= (Y fb × P fb )/P gp

ated widths caused by surface disturbance. Total volume (SCV, cm 3 ) and surface area (SCSA, cm 2 ) of each crack was computed using

the following equations assuming triangular shape of the cracks

where Y fb is the pod yield of french bean, P fb is the price of french

( Bandyopadhyay et al., 2003; Sharma et al., 1995 ):

bean, and P gp is the price of gardenpea. The price t 1 of french bean

varied from US$ 400 to 500 and that of gardenpea from US$ 240 to SCV = 0.5wdl; (3) 360 in different years.

Minimum guaranteed yield that could be obtained relative to SCSA = 2Cl; (4)

maximum observed yield over the years of gardenpea–french bean

cropping system was quantified through sustainable yield index

(SYI), which was calculated by the following expression ( Singh et al., C = [(0.5w) + d ]

where w is the mean width of cracks (cm), d the mean depth of

SYI = (Y − a m (2) the crack (cm), l the length of the crack (cm), and C the parameter

based on w and d.

where Y a is the mean yield, the standard deviation of yield for

that treatment across years, and Y m is the maximum yield obtained 2.4. Soil biological properties

under that treatment in any year. In the concept of SYI, low values

of suggest sustainability of the system ( Efthimiadou et al., 2010 ),

Microbial population of the soil at the end of the experiment was

because measures variation in yield caused by soil parameters enumerated by the soil dilution plate method ( Seeley et al., 1991 ). and climatic factors. If is high, SYI will be low and this indicates Nutrient, rose Bengal, Kenknight agar and Trichoderma selective

unsustainable management practice ( Singh et al., 1990 ). The near- medium (TSM) were used for bacteria, fungi, actinomycetes and

ness of SYI to 1.0 implies the closeness to an ideal situation that can Trichoderma species counts, respectively. To suppress bacteria, sustain maximum crop yields over years, while deviation from 1.0 streptomycin (30 ppm) was added to nutrient agar. In the con-

indicates the losses to sustainability. ventional dilution-plate procedure, 1 g of soil was added to 10 ml

sterile water and tenfold dilution were prepared. From the result-

2.3. Soil physical properties ing suspension portions of 0.1 ml of respective dilution (up to 10 − 7 ,

10 − 5 , 10 − 4 and 10 − 3 for total bacteria, fungi actinomycetes and

Bulk density (BD, Mg m − 3 ) of the surface (0–15 cm) soil layer was Trichoderma species, respectively) were spread with the aid of a

determined using a core sampler (diameter 7 cm and height 8 cm). Drigalsky loop on the surface of agar plates containing 25 ml of

The gravimetric water content of the soil in these sleeves was deter- Nutrient, Rose Bengal, Kenknight agar and TSM medium. The plates

mined on drying at 105 ◦ C. Plant available water capacity (PAWC) were incubated at 28 ◦ C for a week and colony formation units were

was determined as the difference of percentage water content at recorded.

field capacity (0.03 MPa) and permanent wilting point (1.5 MPa) Soil dehydrogenase activity was estimated by reducing 2, 3, using a pressure plate apparatus method. The water infiltration rate 5-triphenyltetrazolium chloride (TTC) ( Casida et al., 1964 ). Five

(IR) was measured using tap water at each of the plots on the soil grams of soil sample were mixed with 50 mg of CaCO 3 and 1 ml

surface using a double ring infiltrometer with a 27 cm outer diame- of 3% (w/v) 2, 3, 5-triphenyltetrazolium chloride and incubated ter and a 15 cm inner diameter, until a constant rate was achieved. for 24 h at 37 ± 1 ◦ C. Dehydrogenase enzyme converts TTC to 2, 3,

Soil temperature was recorded with the help of soil thermometer. 5-triphenylformazan (TPF). The TPF formed was extracted with ace-

The prevalence of weekly soil minimum and maximum tempera- tone (3 × 15 ml), the extracts were filtered through Whatman No. 5

ture of the year across last eight years from the research farm of and absorption was measured at 485 nm with a spectrophotometer.

the experiment has been depicted in Fig. 1 . Soil temperature was Acid phosphatase was assayed using 1 g soil (wet equivalent),

recorded in last year of the experiment during coldest and hottest 4 ml 0.1 M modified universal buffer (pH 6.5) and 1 ml 25 mM

D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427 417

p-nitro phenyl phosphate ( Tabatabai and Bremner, 1969 ). After

3. Results

incubation for 1 h at 37 ± 1 C, the enzyme reaction was stopped by

adding 4 ml 0.5 M NaOH and 1 ml 0.5 M CaCl 2 to prevent dispersion 3.1. Yield attributes and pod yield

of humic substances. The absorbance was measured in the super-

natant at 400 nm; enzyme activity was expressed as ␮g p-nitro Gardenpea and french bean showed significant response to

phenol released g − 1 soil h − 1 .

additional nutrients through FYM. The highest pod numbers per plant were recorded in the plots under FYM 15 and FYM 20 for gar-

denpea and

french

bean, respectively ( Table 2 ). These applications

2.5. Soil chemical properties produced significantly higher number of pods per plant than other

Soil samples were collected from 0–15 cm depth at the end treatments, except FYM 20 and FYM 15 treated plots for of gardenpea the

and french bean, respectively. Plots under FYM

in gardenpea had

6th cropping cycle. Soil pH was determined in 1:2.5 soil:water sus-

plant than NPK and INM treated plots, analyzed respectively, while FYM 20 treated plots under french

34 and 18% higher pods per

pension after shaking for 30 min. These soil samples were

bean

had 36

for organic C by wet digestion using K 2 Cr 2 O 7 and concentrated

and 22% higher than NPK and INM treated plots, respectively. The

H 2 SO 4 ( Walkley and Black, 1934 ). Soil organic C concentrations

were converted from g kg − 1 similar trends

to Mg C ha − 1 using measured soil BD. for respective crops.

were also observed for pod length and plant height

Cation exchange capacity (CEC) of the soil was determined by

The highest mean pod yield of gardenpea was observed in the

yield of FYM K

leaching the soil with KCl followed by extraction of exchangeable

pod

and INM plots in solution was determined flamephoto- 20

plots under FYM 15 ( Table 3 ). The

K by NH 4 OAc and

were similar to FYM 15 for gardenpea crop. But, in the cases

of french

metrically ( Rhoades, 1990 ). Carbon sequestration potential (CSP;

− 1 − 1 bean and

total gardenpea equivalent yield of the system, the high-

Mg ha year ) of a particular treatment was calculated by the est productivity was recorded in the plots under FYM . Two crops

following relationship ( Bhattacharyya et al., 2009 ):

are responding to two different application rates of FYM. Hence, we

have considered the yield of total system CSP = (SOC − SOC )/n (6) for evaluation, as FYM has final initial residual effect for different crop seasons and two different appli-

where SOC final and SOC represent SOC content (Mg C ha − 1 ) cation rates cannot be recommended for

two crops in a system.

The highest productivity of gardenpea equivalent yield at the end of experiment and initial plots, respectively, and ‘n’ indi- of system

initial

cates years of experimentation. Soil organic C budgeting for the was observed

under FYM 20 , which provided 54 and 29% higher pod

studied systems was done as: yield than

NPK and INM treated plots, respectively.

SOC build up rate(Mg C ha − 1 year − 1) 3.2. Sustainable yield index

= (SOC treatment − SOC control )/n (7)

The SYI of the cropping system continued to increase with suc-

cessive levels of FYM and the highest value of 0.606 was recorded

under FYM 20 compared with 0.525 and 0.549 under NPK and INM

where SOC treatment and SOC Control represent SOC content

treated plots, respectively. Similar trends were observed for both

(Mg C ha -1 ) in the FYM or mineral fertilizer applied plots and unfer- crops ( Table 3 ).

tilised control treatment, respectively.

Soil organic carbon (SOC) stored in the soil indirectly reduces the 3.3. Soil physical properties

emission of CO 2 to atmosphere. CO 2 emission reduction through

SOC stock was estimated by the following formula: The soil BD decreased significantly in all treatments compared

with the control plots ( Table 4 ). The BD of plots under 20 t FYM ha − 1

− 1 (1.34 Mg m ) was lower by 0.04 Mg m − 3 and 0.07 Mg m − 3 CO from

2 emission reduction through SOC stock (Mg ha )

NPK and control plots, respectively after six years. PAWC was

= (SOC amount treatment − SOC amount

clearly improved by fertilization ( Table 4 ). The FYM

20 treatment (15.75% PAWC) showed a gain of 5.18 and 0.79% available moisture

control

in the 0–15 cm soil layer over the plots under NPK and INM treat-

The C emission for production, packaging, storage and distri- ments, respectively. Addition of FYM to mineral fertilization (INM)

bution of fertilizers are 1.3 kg carbon equivalent greenhouse gas improved PAWC by 42% over plots under NPK.

emission (CE)/kg N, 0.2 kg CE/kg P 2 O 5 and 0.15 kg CE/kg K 2 O ( Lal,

All treatments significantly reduced the SCV and SCSA than the

2004 ). The CE of FYM is estimated at 0.15 kg/kg N. The CE can be unfertilized control plots and the lowest value was recorded with

converted to CO 2 equivalent by multiplying 3.67. application of 20 t FYM ha − 1 for both parameters. The decrease in

SCV under FYM 20 plots was by 82 and 63% over NPK (324 cm 3 m − 2 surface area) and INM (154 cm 3 m − 2 surface area) plots, respec-

2.6. Statistical analysis tively. The plots under FYM 20 had 83 and 63% less SCSA than NPK

(3111 cm 2 m − 2 surface area) and INM (1424 cm 2 m − 2 surface area)

Statistical analysis of the data was done by using Anova tech- treated plots, respectively.

nique and following SPSS 10.0 and SAS 9.2 software. The treatment The IR increased significantly with the application of FYM, min-

means were compared at P < 0.05 level of probability using student eral fertilizer and INM than control treatment. The highest value of

t-test and working out LSD values. For multifactorial comparison, IR (1.06 cm h − 1 ) was recorded with the application of 20 t FYM ha − 1 . principal component analysis (PCA) and agglomerative hierarchi- INM significantly increased the IR compared to NPK only. There cal clustering (AHC) were used to display the correlation between were improvements of 0.39 and 0.14 cm h –1 IRs under FYM 20 over

the various parameters and their relationship with the different

NPK and INM treated plots, respectively ( Table 4 ). nutrient management practices. Varimax rotation was performed The morning soil temperature of coldest week (second week of

to produce orthogonal transformations to the reduced factors to January) increased significantly in all treatments compared to the

identify the high and low correlations better. Multifactorial analysis control plots. The soil temperature under FYM 20 plots (10.78 ◦ C) was carried out using the XLSTAT software (XLSTAT 2010). was significantly higher than NPK (10.27 ◦ C) and INM (10.37 ◦ C)

418 D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427

Table 2

Effect of farmyard manure (FYM) on yield attributes of gardenpea and french bean (mean of six years).

Treatments a Gardenpea French bean

Pod number plant − 1 Pod length (cm) Plant height (cm) Pod number plant − 1 Pod length (cm) Plant height(cm)

Control 6.53 6.29 43.6 7.6 10.5 31.9 FYM 5 8.35 6.69 56.2 9.6 11.9 44.0 FYM 10 9.54 6.86 63.7 11.7 12.6 51.3 FYM 15 11.09 7.18 70.1 12.8 12.9 54.2 FYM 20 11.02 7.10 68.1 13.7 13.2 57.2 NPK 8.30 6.69 55.8 10.1 12.3 46.5 INM 9.43 6.84 62.7 11.2 12.5 50.4

SEM ± 0.36 0.07 1.9 0.5 0.2 1.6 LSD (P = 0.05) 1.05 0.20 5.6 1.4 0.6 4.6

a See Section 2 for treatment details. LSD = Least significant difference. SEM = Standard error of mean.

Table 3

Mean (of six years) productivity and sustainability of gardenpea–french bean cropping system under different nutrient management practices in the Indian Himalayas.

Treatments a Mean pod yield (t ha − 1 ) Sustainable yield index

Gardenpea French bean Gardenpea equivalent Gardenpea French bean Gardenpea –french

yield of total system bean cropping system

Control 3.42 4.12 10.04 0.637 0.318 0.472 FYM 5 6.04 8.93 20.12 0.676 0.399 0.482 FYM 10 7.60 11.19 25.18 0.680 0.436 0.521 FYM 15 9.12 12.83 29.24 0.682 0.486 0.564 FYM 20 8.90 14.44 31.47 0.705 0.517 0.606 NPK 5.96 9.14 20.49 0.615 0.381 0.525 INM 7.07 10.97 24.36 0.684 0.466 0.549 SEM ± 0.37 0.75 1.07 – – – LSD(P = 0.05) 1.06 2.16 3.08 – – –

a See Section 2 for treatment details. LSD = Least significant difference. SEM = Standard error of mean.

plots. The FYM 20 treatment had a significant decrease in temper- significantly higher than the population levels recorded in the plots

ature in the 0–15 cm soil layer over the plots with NPK and INM under NPK and INM. The fungal population under FYM 20 (5.18 × 10 5 during afternoon of the coldest and hottest week and morning colony formation unit g − 1 soil) were 350 and 27% higher than the

temperature of the hottest week. The temperature difference dur- plots receiving NPK and INM, respectively. It was further observed

ing the day was lowest with application of 20 t FYM ha − 1 among

that the plots under FYM 20 recorded significantly higher levels of

other nutrient source plots. It indicates that the diurnal variation actinomycetes (140 and 48% higher than NPK and INM, respec-

in temperature is low with application of high rate of FYM (FYM 20 )

tively) and Trichoderma spp. (304 and 60% higher than NPK and

compared to NPK and INM treated plots. INM, respectively). There was at least 150% increase in microbial

population with addition of FYM to mineral fertilizer over NPK

3.4. Soil biological properties alone.

Basically, the enzyme involved in intracellular microbial In general, it was observed that continuous application of FYM metabolism, i.e., dehydrogenase and the enzyme responsible for

had a beneficial effect on the population levels of total bacteria, solubilizing P from soil i.e. acid phosphatase, increased with appli-

fungi, actinomycetes and Trichoderma spp. in the surface layer cation of FYM, mineral fertilizer and INM ( Table 5 ). Dehydrogenase

(0–15 cm) of soil after six years of crop cycle ( Table 5 ). The least and acid phosphatase activity increased with each incremental population was recorded in the unfertilized control plots for afore- application of FYM and the highest activities of these enzymes were

mentioned microbes. Plots under FYM 20 had the highest bacterial estimated with application of 20 t FYM ha − 1 among all treatments.

population (3.92 × 10 7 colony formation units g − 1 soil), which was The dehydrogenase activity under FYM 20 plots were 93 and 26%

Table 4

Effects of fertilization on soil physical properties after six years of irrigated gardenpea–french bean cropping system.

Treatments a BD PAWC

SCV

SCSA

IR

Soil temperature during the last year of experimentation ( ◦

C)

(Mg m − 3 ) b (%)

(cm 3 m − 2 area)

(cm 2 m − 2 area)

(cm h − 1

Coldest week of year Hottest week of year Temperature Morn AN Temp diff diff

difference Morn AN Temp

within year

Control 1.41 8.89 401 4232 0.63 11.0 15.1 4.07 24.2 29.1 4.87 13.6 FYM 5 1.37 10.09 186 1819 0.73 11.6 14.3 2.67 23.8 27.6 3.80 12.8 FYM 10 1.36 11.84 206 1990 0.77 11.9 14.0 2.17 23.6 25.9 2.30 11.8 FYM 15 1.35 14.09 177 1974 0.97 12.1 13.6 1.53 23.6 24.6 1.03 11.3 FYM 20 1.34 15.75 57 531 1.06 12.5 13.3 0.77 23.5 24.1 0.60 10.9 NPK 1.38 10.57 324 3111 0.67 11.9 14.3 2.43 24.0 27.0 3.03 12.4 INM 1.35 14.96 154 1424 0.92 12.0 13.6 1.57 23.7 24.8 1.10 11.4

SEM ± 0.005 0.79 15 101 0.004 0.1 0.1 0.1 0.3 LSD(P = 0.05) 0.014 2.43 45 310 0.012 0.4 0.4 NS 0.9

a See Section 2 for treatment details. LSD =

b Least significant difference. SEM = Standard error of mean. BD = Bulk density; PAWC = Plant available soil water capacity; SCV = Soil crack volume; SCSA = Soil crack surface area; IR = Infiltration rate; Morn = morning; AN = Afternoon;

Temp diff = temperature difference.

D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427 419 Table 5

Effects of fertilization on soil biological properties after six years of irrigated gardenpea–french bean cropping system.

Treatments a Microbial population count (CFU b g − 1 soil) Soil enzymatic activity

Bacteria

Fungi

Actinomycetes

Trichoderma

activity

Acid phosphatase activity

Dehydrogenase

spp. (×10 3 )

(␮g TPF g −

1 soil 24 h − 1 )

(␮g PNP g − 1 soil h − 1 ) Control 1.10 1.09 6.85 1.14 67.5 994

FYM 5 1.72 2.11 12.59 2.08 78.7 1038 FYM 10 1.91 3.26 13.45 2.59 103.9 1142 FYM 15 2.68 4.59 22.73 4.45 127.1 1249 FYM 20 3.92 5.18 27.15 4.96 148.1 1410 NPK 1.68 1.15 11.32 1.23 76.7 1031 INM 2.62 4.09 18.28 3.11 117.7 1238

SEM ± 0.16 0.19 0.84 0.16 7.1 64 LSD(P = 0.05) 0.50 0.59 2.60 0.48 21.9 197

b See Section 2 for treatment details. LSD = Least significant difference. SEM = Standard error of mean. CFU = Colony forming unit.

higher than NPK and INM treated plots, respectively. About 37 and

14% higher acid phosphatase activities were recorded under soils

of FYM 20 than NPK and INM treatments, respectively.

3.5. Soil chemical properties

Application of FYM, mineral fertilizer (NPK) and integration of

both organic and mineral source of nutrients (INM) significantly

influenced all selected soil chemical properties in the 0–15 cm

depth ( Table 6 ). Application of NPK recorded the lowest soil pH value (5.64), which was 0.46 (7.5%) lower than the initial value.

Addition of FYM to mineral fertilizer improved the soil reaction in

INM. The soil pH increased significantly in all plots treated with

FYM compared with mineral fertilization. Application of FYM 20 recorded the highest soil pH value (6.85) and was near neutral

range, which was ∼ 21.5% higher than NPK plots. The pH increased

from 6.65 to 6.85 as the level of FYM application increased from 5

to 20 t ha − 1 .

SOC is an overall indicator of soil quality ( Lopez et al., 2012 ).

Soil organic C concentrations decreased from their initial values Fig. 2. Soil organic carbon sequestration potential (CSP) of different nutrient man-

agement practices under in the plots under unfertilized control. Soils under FYM treat- an irrigated gardenpea–french bean cropping system in ment (13.2 g C kg −

(see Section 2 for treatment details). ) contained 14.1 and

9.3% higher SOC in the

the Indian Himalayas

0−15 cm soil layer compared with NPK and INM treated plots,

respectively. The SOC concentration increased with every succes- 3.6. Correlation and PCA of pod yield with soil property

sive increment of FYM application from 5 to 20 t FYM ha − 1 . The

amount of SOC under FYM 20 plots (26.6 Mg ha − 1 ) was increased A correlation matrix ( Table 7 ) showed significant correlations

by 2.6 and 2.1 Mg ha − 1 compared to NPK and INM treated plots. (P < 0.05) between all the different soil parameters and pod yields

All treatments significantly improved soil CEC than control plots, of both gardenpea and french bean, except soil pH. There was very

except plots under NPK. Application of FYM 20 recorded the high- strong correlation (P < 0.001) between SOC and CEC, SOC and BD,

est soil CEC value (13.03 c mol kg − 1 ), which was 2.5 (24%) and

PAWC with bacterial, actinomycete population, dehydrogenase and

1.23 c mol kg − 1 (10%) higher than NPK and INM plots, respec-

tively.

Carbon sequestration potential (CSP), defined as the rate of increase in SOC content over the initial soil in the 0–0.15 m soil

depth, ranged from − 0.534 Mg C ha − 1 year − 1 in the unfertilized control plots to 0.527 Mg C ha − 1 year − 1 in the plots under FYM 20 ( Fig. 2 ). CSP was negative in the unfertilised control plots. The CSP

of FYM 20 plots was about 0.433 and 0.347 Mg C ha − 1 year − 1 more than NPK and INM plots, respectively. There was an increase net

build-up rate of total SOC in the plots under FYM 20 , the mean mag-

nitude being 69 and 49%, respectively, over NPK and INM treated

plots ( Fig. 3 ). The gardenpea equivalent pod yield of the system was

positively related (R 2 = 0.934) to SOC content ( Fig. 4 ). The CO 2 emis- sion reduction under FYM 20 plots was up to 9.5 and 7.6 Mg ha − 1 compared to NPK and INM plots, respectively, through gain in SOC

stock. Again the CO 2 equivalent annual emission of GHGs from

production of 20 t FYM was 53 and 24% less than applied min-

eral fertilizer and FYM under recommended NPK and INM plots, Fig. 3. Soil organic carbon (SOC) build-up rate in different nutrient practices management under gardenpea–french bean cropping system (see Section 2 for treat-

respectively ( Table 6 ).

ment details).

420 D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427

Table 6

Effects of fertilization on selected soil chemical properties and carbon equivalent emission from irrigated gardenpea–french bean cropping system after six years.

Treatments a pH SOC b SOC

CO 2 emission

CO 2 equivalent emission from Soil CEC

concentration

amount/stock

reduction through SOC production of nutrient (c mol − − 1 1 kg )

(g kg )

(Mg ha − 1 )

stock (Mg ha − 1 )

(kg ha − 1 yr -1 )

Control 6.11 9.54 20.2 – – 9.07 FYM 5 6.65 11.88 24.4 15.5 56 11.36 FYM 10 6.72 12.35 25.2 18.4 112 11.92 FYM 15 6.78 12.59 25.5 19.5 168 12.30 FYM 20 6.85 13.21 26.6 23.3 224 13.03 NPK 5.64 11.57 24.0 13.8 479 10.53 INM 6.30 12.08 24.5 15.7 295 11.80

SEM ± 0.13 0.50 1.0 0.53 LSD(P = 0.05) 0.39 1.53 3.1 1.63

a See Section 2 for treatment details. LSD = Least significant difference. SEM = Standard error of mean.

b SOC = soil organic carbon.

acid phosphatase activity, french bean pod yield with CEC, SOC

from a treatment point to a variable line approximates the value

and BD, and IR with fungal, actinomycetal, Trichodermal population, of that observation on the variable that the line represents. If the

dehydrogenase and acid phosphatase activity. There were also very cut point falls on the origin, the value of the observation is approx-

strong (P < 0.001) to strong (P < 0.01) relationships among microbial imately the average of the respective variable. Cut points far off

populations and enzymatic activities. The microbial populations in the direction of the variable line indicate high values, while cut

and soil enzymatic activity were more correlated to CEC (P < 0.01) points far off on the variable line, which has been extended through

than organic carbon (P < 0.05). There was also very strong positive the origin, represent low values ( Kohler and Luniak, 2005 ). Super-

(P < 0.001) correlations between IR and PAWC as contrary to general imposition of nutrient management practices and yield along with

perception. Soil pH had no correlation (P > 0.05) to any of the soil soil properties showed that FYM 20 and FYM 15 showed higher corre-

parameters and pod yield of both crops, except Trichoderma popu- lation with these parameters. It was confirmed from the correlation

lation. The BD, soil cracking volume and surface area, temperature in Table 7 and PCA in Fig. 5 that soil CEC followed by SOC were very

at hottest week afternoon and diurnal temperature difference of closely correlated with pod yield of both vegetables. Hence, Soil CEC

hottest week were negatively correlated with other parameters. followed by SOC were the most important yield contributing soil

PCA is a useful statistical technique which had found applica- properties. Soil pH was least important property for contributing

tion in reduction of the original variables in a smaller number of productivity and influencing other soil property.

underlying variables (principal component) in order to reveal the The PCA of nutrient management practices comprising two prin-

interrelationships between the different variables and to find the cipal components (F1 52.3%; F2 40.8% for gardenpea and F1 89.4%;

optimum number of extracted principal components. The different F2 4.5% for french bean) accounted for 93.1 and 93.9% of variance for

soil properties and pod yield of crops were depicted in Fig. 5 . The gardenpea and french bean, respectively. The F1 and F2 had a clus-

PCA comprising two principal components (F1 and F2) accounted ter of nutrient management practices (FYM 20 , FYM 15 and INM) with

for 93.1% and 93.9% of variance for gardenpea and french bean large positive loading for the first component. The second compo-

crops, respectively. nent also positive for gardenpea, except slight negative for INM,

The longer the line in PCA, the higher is the variance. The vari- while these were slight negative for french bean crop. Nutrient ance among the variables in the biplot was almost similar for both management practices NPK and control had negative loading for

gardenpea and french bean ( Fig. 5 ). The cosine of the angle between first and second component for both crops. Other nutrient man-

the lines approximates the correlation between the variables they agement practices occupied positions either on left upper or right

represent. The closer the angle to 90 or 270 ◦ , the smaller was upper side of the biplot.

the correlation. An angle of 0 or 180 ◦ reflects a correlation of 1 The position of 17 parameters in relation to their influence by

or − 1, respectively ( Kohler and Luniak, 2005 ). The biplot in Fig. 5 nutrient management practices accounted for 93.1 and 93.9% vari-

showed a strong positive relationship between the pod yield and ance for gardenpea and french bean, respectively. For gardenpea,

CEC, SOC, all microbial population count, both enzymatic activity, all parameters except BD, soil cracking volume and soil cracking

IR and PAWC for both vegetables. The cut point of a perpendicular surface area occupied positions solely on the right upper part of

Fig. 4. Response of soil organic carbon (SOC) and cation exchange capacity to gardenpea equivalent yield of the system (SOC, soil cation exchange capacity and gardenpea

equivalent yield of the system values of different treatments were taken for this response calculation).

Table 7

Correlation between pod yield of gardenpea and french bean and soil properties.

a GPY FBY SOC CEC pH Bact Fungi Actino Tricho DHA AcP PAWC BD SCV SCSA IR CWM HWA HWD

GPY 1.000 0.951 **

FBY 1.000 0.979

SOC 1.000 0.986 ***

CEC 1.000

pH 1.000 0.572 0.748 0.634 0.759 *

Bact 1.000

Fungi 1.000 0.944 **

Actino 1.000

Tricho 1.000 0.971 ***

DHA 1.000

AcP 1.000 0.985 ***

PAWC 1.000

BD 1.000 0.949 **

* 0.855 * * SCSA

SCV 1.000

IR 1.000

0.849 * − 0.935 ** − 0.931 ** CWM 1.000 HWA 1.000

D. HWD 1.000

Mahanta

a GPY = Gardenpea po yield; FBY = French bean pod yield; SOC = Soil organic carbon content; CEC = Soil cation exchange capacity; Bact = Bacterial population count [colony forming unit (CFU) g − 1 soil]; Fungi = Fungal population

count (CFU − g − 1 soil); − Actino = Actinomycete population count (CFU g − 1 soil); Tricho = Trichoderma species − − population count (CFU g 1 soil); − DHA = Dehydrogenase activity (␮g TPF g − − 1 soil 24 h − 1 ); AcP = Acid phosphatase activity

(␮g PNP g 1 soil h 1 ); PAWC = Plant available water capacity (%); SCV = Soil crack volume (cm 3 m 2 ); SCSA = Soil crack surface area (cm 2 m 2 ); IR = Infiltration rate (cm h 1 ); CWM = of the coldest week in ◦ Morning temperature the et year ( C); HWA = afternoon temperature of the hottest week in the year ( ◦ C); HWD = Diurnal temperature difference of the hottest week in the year ( ◦ C). al.

p < 0.05. / Scientia

p < 0.01.

p < 0.001. Horticulturae

III Fig.

Composition Table FYM

The

in

these

site

positions.

except

crops

tive

parameters

tioning

side

diurnal

cracking

the

II I Cluster

ysis

biplots. (see 5. -- 15 axis F2 (40.80 %) --> cluster crops 8 -- axis F2 (4.52 %) -->

As

enhancing The

to

similar showed of

Multifactorial 0.5

no.

and

a three

BD, interpretation the variation Table -1

0.5 -1

0 1 -1

of

of INM result Again ( surface

Gardenpea

nutrient

SCV,

I Figs.

by

the

For

biplot. SCSA

SCV

HWA

BD HWD

French bean

clusters

possessed

soil

for Variab

2 2 3 management Number

positions

Tables (

of

that

BD

property soil

SCSA, 5 and nutrient of french area,

superimposition 414–427

FYM les afte abbreviations

the comparison SCV

of cluster

management

BD,

soil

6 hottest -0.5 Variables (axes F1 and F2: 93.8

of nutrient

r Vari practices and

nutrient 8 nutrient

HWA, of

of

SCV,

temperature, bean,

and FYM FYM , Superimposition

the

SCSA

analysis,

managements

except axis F1

of soil

management SCSA, PCA

axis F1

ma

), which

week

20 HWD crop 15 used).

practices , FYM of

xrot

management

and

respective

results

properties

three

HWA

afternoon

ation

productivity.

and

all BD,

Control, FYM FYM Nutrient

(axes F1 and F best

practices are 15 INM

and

of

and soil group

can

parameters

soil

using %) -->

pH

clusters

20 had

5 and

-->

be

NPK FYM

INM.

HWD

FYM , , both

pH

PCA

soil cracking

principal

explained 15

10 management

based discernible practice direct all and

SOC

, INM were This

occupied occupied

PCA

plots temperature soil 0.5 pH

on occupied CEC

PCA involvement group of

meant

parameters

for volume,

component

CWM

by Fungi

practices value. of

Tricho

GPY

obtained.

respective

by AcP Bact

SOC

Bact

FYM

their oppo- posi- right that

similar

respec-

of

PAWC

PAWC

and anal- 1 soil Fungi soil IR FBY CEC

DHA

Actino

AcP Act Tricho IR 20 DHA 1 ino

422 D. Mahanta et al. / Scientia Horticulturae 164 (2013) 414–427

Fig. 6. Grouping of nutrient management practices based on principal component scores (see Section 2 for treatment details).

highest mean values of positive influencing soil parameters and

showed that differences in these parameters were associated with

lowest mean values for negative influencing soil parameters. The differences in SOC. The moderation of soil temperature through

next best cluster was II, which retained FYM 5 and FYM 10 nutrient

nutrient management during coldest and hottest week compared

management practices, followed by cluster III (control and NPK). to un-amended control plots was positively and linearly correlated

The grouping pattern of nutrient management practices observed with gardenpea and french bean crop, respectively. (R 2 = 0.8339