Eggshell powder as calcium source on growth and yield of groundnut (Arachis hypogaea L.)

Figures & data

Table 1. Ingredients in eggshell powder*.

Main Properties	Value	Main Properties	Value
Humidity	1.57%	Mn-citrate	0.01%
N	0.74%	B-citrate	≥ 0.002%
P	0.26%	Fe	0.017%
K	0.08%	Cu	0.0002%
CaCO3	88.08%	Zn	0.0001%
Mg-citrate	0.57%	Mo	0.0001%
Alkalinity	50.18%	pH	10.1

*The data were supported by Green Techno 21 Company of Japan

Table 2. The initial physical and chemical properties of the experimental soil.

Parameters	Values
pH	6.51
Organic matter (%)	1.67
Total N (%)	0.09
Total P (%)	0.18
Total K (%)	1.34
Total Ca (%)	0.07
Exchangeable N (mg/100 g)	4.27
Exchangeable P (mg/100 g)	50.02
Exchangeable K (mg/100 g)	11.80

Table 3. Effects of application times and rates of eggshell powder on plant height (PH), branch length (BL), shoot weight (SW), and root weight (RW) of L27 groundnut cultivar.

Time	Rate	PH (cm)	BL (cm)	SW (g plant^−1)	RW (g plant^−1)
T1	A0	27.8^abc	27.2^bc	26.5^bcd	1.15^bc
	A1	28.1^abc	27.5^abc	26.9^bc	1.16^bc
	A2	29.4^a	29.7^a	31.6^a	1.36^a
	A3	28.6^ab	28.7^ab	26.3^bcd	1.16^bc
	A4	27.9^abc	27.4^abc	25.3^cde	1.14^bc
T2	A0	25.9^c	25.6^c	24.5^de	1.05^c
	A1	26.3^bc	25.7^c	24.5^de	1.10^bc
	A2	26.5^bc	25.8^c	25.2^cde	1.13^bc
	A3	28.2^abc	27.6^abc	27.8^b	1.20^b
	A4	26.5^bc	27.4^c	24.0^e	1.16^bc
Source of variation
Application time (T)		ns	*	*	*
Application rate (A)		*	**	***	***
T x A		ns	ns	***	***

Note: T1 = Application before sowing; T2 = Application after flowering; A0 = application of lime at rate of 500 kg ha⁻¹, A1, A2, A3 and A4 = application rates of 200, 300, 400 and 500 kg ha⁻¹ of eggshell powder, respectively. Different alphabet letters show significance among treatments at p < 0.05 by the Tukey test. ns, *, **, *** means non-significant, significant at p < 0.05, 0.01 and 0.001, respectively.

Table 4. Effects of application times and rates of eggshell powder on leaf area, SPAD, nodule number (No.N), and nodule dry weight (NW) of L27 groundnut cultivar.

Time	Rate	Leaf Area (dm^2)	SPAD	No.N (Nodule)	NW (g Plant^−1)
T1	A0	8.66^a	42.4^a	251.7^ab	0.277^de
	A1	8.91^a	42.7^a	258.3^ab	0.307^d
	A2	9.40^a	44.1^a	267.5^a	0.463^a
	A3	9.31^a	43.4^a	269.2^a	0.410^b
	A4	8.96^a	42.2^a	257.3^ab	0.367^c
T2	A0	8.35^a	41.0^a	220.8^d	0.213 ^f
	A1	8.53^a	41.2^a	222.5 ^cd	0.233 ^f
	A2	8.65^a	41.9^a	237.5^bcd	0.240^ef
	A3	8.83^a	43.3^a	244.2^bc	0.280^d
	A4	8.62^a	41.7^a	242.5^bcd	0.210 ^f
Source of variation
Application time (T)		*	**	**	**
Application rate (A)		ns	ns	**	***
TxA		ns	ns	ns	***

Note: T1 = Application before sowing; T2 = Application after flowering; A0 = application of lime at rate of 500 kg ha⁻¹, A1, A2, A3 and A4 = application rates of 200, 300, 400 and 500 kg ha⁻¹ of eggshell powder, respectively. Different alphabet letters show significance among treatments at p < 0.05 by the Tukey test. ns, *, **, *** means non-significant, significant at p < 0.05, 0.01 and 0.001, respectively.

Table 5. Effects of application times and rates of eggshell powder on number of filled pods (No.P), 100-pods weight (100P-W), 100-seeds weight (100S-W), shelling percentage (%), and pod yield of L27 groundnut cultivar.

Time	Rate	No.P (Pod Plant^−1)	100-PW (g)	100-SW (g)	Shelling % (%)	Pod Yield (Tones ha^−1)
T1	A0	9.7^abc	141.1^abcd	54.9^abc	70.4^a	2.76 ^cd
	A1	9.3^bc	142.6^abc	57.2^ab	66.3^a	2.83 ^cd
	A2	11.0^a	146.1^a	58.7^a	73.5^a	3.60^a
	A3	10.9^a	143.9^ab	56.3^ab	73.8^a	3.30^ab
	A4	10.0^abc	142.8^abc	56.2^ab	72.0^a	3.25^ab
T2	A0	9.1^c	133.2^d	47.4^d	72.7^a	2.69^d
	A1	9.1^c	134.2^d	48.8^d	68.3^a	2.68^d
	A2	10.2^abc	135.1 ^cd	50.6 ^cd	71.1^a	2.79 ^cd
	A3	10.7^ab	136.1^bcd	51.9^bcd	72.3^a	3.11^bc
	A4	9.9^abc	134.4^d	52.1^bcd	68.2^a	2.65^d
Source of variation
T		ns	**	**	ns	*
A		***	ns	*	*	***
T x A		ns	ns	ns	ns	***

Note: T1 = Application before sowing; T2 = Application after flowering; A0 = application of lime at rate of 500 kg ha⁻¹, A1, A2, A3 and A4 = application rates of 200, 300, 400 and 500 kg ha⁻¹ of eggshell powder, respectively. Different alphabet letters show significance among treatments at p < 0.05 by the Tukey test. ns, *, **, *** means non-significant, significant at p < 0.05, 0.01 and 0.001, respectively.

Figure 1. Correlation between amount of calcium application and pod yield of groundnut before sowing (open shape) and after flowering (closed shape); Different shapes indicate lime and rates of eggshell powder application as follows: circle – A0 (500 kg ha⁻¹ lime, equivalent to 200 kg ha⁻¹ Ca), triangle – A1 (200 kg ha⁻¹ eggshell powder, equivalent to 70 kg ha⁻¹ Ca), rectangle – A2 (300 kg ha⁻¹ eggshell powder, equivalent to 106 kg ha⁻¹ Ca), diamond – A3 (400 kg ha⁻¹ eggshell powder, equivalent to 141 kg ha⁻¹ Ca), and square – A4 (500 kg ha⁻¹ eggshell powder, equivalent to 176 kg ha⁻¹ Ca); Error bars present the standard deviation.

Figure 2. Effects of application rates and time of eggshell powder on soil pH, soil calcium content, plant calcium content, and total plant calcium uptake in groundnut.

Note: T1 = Application before sowing; T2 = Application after flowering; A0 = application of lime at rate of 500 kg ha⁻¹, A1, A2, A3 and A4 = application rates of 200, 300, 400 and 500 kg ha⁻¹ of eggshell powder, respectively. Different capital letters show significant differences between application times at p < 0.05 by the Tukey test. Different lowercase letters show significant differences among lime and eggshell powder treatments at p < 0.05 by the Tukey test; Error bars present the standard deviation.